BFO-Intro
PHI 598LEC Introduction to Basic Formal Ontology
Spring 2026
Faculty: Dr. Barry Smith
ONLINE, HYBRID, TWO CREDIT COURSE
This course will present an introduction to Basic Formal Ontology (BFO), which is a widely used top-level ontology, approved in 2021 as international standard ISO/IEC 21838-2. The course is divided into an asynchronous and a synchronous part, as follows:
The asynchronous part
This will consists of a series of videos listed in week-by-week order below. (The complete list will be made available soon.) Typically I will present suggestions for background reading which might be of assistance in absorbing the content of these videos. Where students have comments or questions relating to a specific video, comments which they believe will be of general interest to other students in the class, these should be submitted to the Teams channel (to be established), where Dr Smith will provide responses. More specific questions, for example about logistics, can be emailed to Dr Smith at ifomis@gmail.com.
You will find further treatment of many of the issues addressed in the videos in the BFO textbook, which is listed under Background Reading below.
Note that questions and all other contributions, whether communicated through zoom meetings, emails or via Teams, will form part of the material used for grading this class.
The synchronous part
This will consist of practical work by students, either working alone or (preferably) as members of teams. The results of this work will then be communicated through a series of zoom meetings, supplemented by associated discussions on our Slack channel.
Students will participate in working sessions designed to lead to the creation of online content -- essays, videos, articles, ... -- for example summarizing (or criticizing) aspects of BFO or describing how BFO can be used in specific areas, or reviewing what results when LLMs are used in BFO coding, or how BFO helps you solve a problem at work. Ideally the content should be suitable for distribution to a wider audience. These working sessions will involve teams, which will be put together in the early weeks of the class with the aid of Elena Miliventi, who is my research assistant (and also a student in this glass). It is hoped that one team will address the charges made against BFO in the paper BFO Expert Coding Challenge (perhaps considering also the Citations to this paper). Other ideas are: a series of tiktok videos or LinkedIn contributions presenting key aspects of BFO; articles intended for publication; projects demonstrating the utility of BFO e.g. for solving problems you face at work, proposals to improve BFO, and so on. Here creativity will contribute to your grade for this class.
For those students who have a suitable project which they wish to realize on their own, regular meetings with Dr Smith and/or with Ms Miliventi will be organized.
Working sessions are tentatively scheduled to take place from 7-8pm as listed in the table below.
Week 1 (January 21): Inaugural session
Week 2 (January 28): Basic Formal Ontology 101 Video
- This is an introduction to building ontologies with BFO, with special reference to the rules for deciding whether a given general term designates a universal.
Week 3 (February 4): BFO Tutorial (2019): A series of 6 Videos
- This is a survey of main features of BFO itself in the form of a series of short tutorials. It deals with BFO 2.0, which differs slightly from BFO 2020, which is the most current version. However the differences relate not to BFO itself, but rather to the new First Order Logic axiomatization of BFO, which was introduced with the ISO standard. Details (for those who are interested in such matters) can be found here: https://ncorwiki.buffalo.edu/index.php/BFO_Release_History.
Week 4 (February 11): Basic Formal Ontology Tutorial Video
- This is a presentation to an audience of engineers at a meeting of the Industrial Ontologies Foundry. It contains examples of what happens when people argue about BFO. BFO is a realist ontology, which means that all terms of BFO are intended to refer to something that exist. How, then, do we provide a BFO-conformant treatment of the work of an industrial designer, at the point where the object he is designing does not yet exist?
Week 5 (February 18): The Ontology of Science
- Focuses on the Focuses on the ontology of biology, and on the issue of multi-level ontology -- from molecules to cells to organisms, and from functions at the molecular level to downstream biological processes. BFO claims to be a multi-perspectival ontology, and in particular a multi-granularity ontology, which can work on each of these levels.
Week 6 (February 25): Aboutness and Language
- BFO does not contain terms relating to information entities such as words or mathematical equations or poems. Instead it draws on the category of generically dependent continuants (GDCs), which then forms the starting point of the Information Artifact Ontology. Information artifacts are GDCs which are about something.
Week 7 (March 4): Ontology of Terrorism
- Acts of terrorism are often described in terms of "sending a message" (for example to a government) through violence or threats of violence. We present the beginnings of an ontology of terrorism on this basis, drawing on the theory of speech acts but also on a more general theory of language according to which a language is a set of capabilities associated with a set of behaviors.
Week 8 (March 11): Capabilities (2022); BFO and DOLCE
- The first of these two videos proposes a definition of capability as a universal falling between function and disposition as the latter are defined in Basic Formal Ontology (BFO). Capabilities are like functions in that they can be evaluated on the basis of how well they are realized. They differ from functions in that they are not the rationale for the existence of their bearers. Thus, a water pump may have, in addition to its function of pumping water, many capabilities including: to be weatherproof, to run without lubricant, and so forth. We argue, that all functions are capabilities, but not all capabilities are functions, and we develop a series of axioms to distinguish capabilities formally from both dispositions and functions. We provide examples of the use of capability in a variety of domains, focusing on a definition of language as a capability of persons.
- The second video presents a view of how BFO functions as a support for its users.
Week 9 (March 25) JOWO Part 1, Part 2, Temporalized Relations
- Begins with a 2-part video of a tutorial presented at the JOWO (Joint Ontologies Workshops). Part 1 introduces BFO to a technical audience. Part 2 provides a brief exposition of the rationale for including temporalized relations in the OWL specification of BFO 2020 (ISO/IEC 21838:2). Since OWL can accommodate only two-place relations, and since the de facto standard formalization of BFO uses OWL, there is a need for strategies to capture the temporal dimensions of general assertions such as "Milk teeth are lost as children grow" or "Thermally heated machines are inspected every 6 months." The third video provides an attempt at a simplified exposition of the issues involved.
Week 10 (March 11)
| # | Topics | Related links | ||
|---|---|---|---|---|
| 2 | top-level vs domain ontologies; top of BFO | |||
| 3 | functions, dispositions, capabilities | https://www.youtube.com/watch?v=lIPg2bGJSzE | ||
| 4 | sites, boundaries | https://studio.youtube.com/video/gxihMdMiV0Y/edit | ||
| 5 | temporalized relations | https://www.youtube.com/watch?v=fkkWkTIxrNQ | ||
| 6 | social wholes, dispositions and roles | |||
| 7 | material entities; object aggregates | |||
| 8 | processes, process profiles, changes, | last part of https://www.youtube.com/watch?v=7sbzF9p7qvk | ||
| 9 | IAO, language, aboutness | https://www.youtube.com/watch?v=Y3btP1InPZY, https://studio.youtube.com/video/PBKsupBquok/edit | ||
| 10 | BFO 101 | https://www.youtube.com/watch?v=7sbzF9p7qvk | ||
| 11 | BFO vs. DOLCE | https://www.youtube.com/watch?v=XTVR7k63_VA | ||
| 12 | Foundries | |||
| 13 | GDCs, Ingarden, the State | https://studio.youtube.com/video/4HqRrPIWsDk/edit | ||
| 14 | Synchronous question answer session | |||
| 15 | Synchronous question/answer session |
Material for the course will be based on the following BFO tutorials, supplemented by documentation of more recent developments:
Revised versions of this tutorial material will be divided into 14 (roughly) single-hour lectures, which will be made available asynchronously. The lectures will form part of the basis for synchronous working sessions, in which students will be divided into teams. Each month all students will give presentations on the results of their work thus far.
Grading
Students will be graded on the basis of:
- 1. questions (and answers) assembled by students over the course of the semester
- For each video, the student should prepare exactly one single-sentence question relating to the content of this video, together with a 1-paragraph answer to this question. The answer should not be contained in the video content for this class. All questions and answers should be sent in a single email to ifomis@gmail.com on April 30.
- 2. interactions and results of the synchronous phase
- Dr Smith and Ms Milivinti will keep track of your interactions in support of your creative work during the course of the semester. Dr Smith will evaluate this content and also results of your work. Features to be graded will include: creativity, quantity of your contributions, success of your project(s).
Both 1. and 2. determine 50% of the total grade. Where team work is graded members of teams will receive equal grades.e
Background reading
Grokipedia on Basic Formal Ontology
[1] R. Arp, B. Smith, A. Spear, Building Ontologies with Basic Formal Ontology, Cambridge MA: MIT Press (2015).
[2] Jansen, Ludger, and Barry Smith. "Categories in Top-Level Ontologies: Revisiting the Aristotelian Background," Advances in Knowledge Representation, 5(3) (2025).
[3] Peter M. Simons, "Against Set Theory", in: Experience and Analysis, Vienna: HPT&ÖBV, 143-152 (2005).
[4] Barry Smith, "Beyond concepts: ontology as reality representation," in: Proceedings of the Third International Conference on Formal Ontology in Information Systems (FOIS 2004), 73-84. Amsterdam: IOS Press, 2004.
| # | Video Title | Duration | YouTube Link |
|---|---|---|---|
| 1 | Basic Formal Ontology 101 (July 2025) | 1:58:50 | https://www.youtube.com/watch?v=7sbzF9p7qvk |
| 2 | Basic Formal Ontology Tutorial (2025) | 1:46:05 | https://www.youtube.com/watch?v=GWkk5AfRCpM |
| 3 | The Ontology of Science | 1:06:08 | https://www.youtube.com/watch?v=PwsBxRs9kns |
| 5 | Basic Formal Ontology (BFO), July 2023 | 10:20 | https://www.youtube.com/watch?v=uflMfvI-ZxI |
| 6 | The Ontology of (Supply Chain) Services | 11:35 | https://www.youtube.com/watch?v=F1Zlunh3eMw |
| 7 | Industrial Ontologies Foundry (2022) | 7:52 | https://www.youtube.com/watch?v=1pfsimHTApU |
| 8 | Ontology of (Social) Services | 10:38 | https://www.youtube.com/watch?v=9qrwWAISrC8 |
| 9 | Ontology Foundries | 20:51 | https://www.youtube.com/watch?v=iFiwmq7f4wQ |
| 10 | ISO/IEC 21838 Top Level Ontologies (November 2021) | 10:57 | https://www.youtube.com/watch?v=YsdcH-yYkTI |
| 11 | Realizable Entities in Basic Formal Ontology | 1:36:36 | https://www.youtube.com/watch?v=PJaEYdF9ikE |
| 12 | How to handle data about what does not exist | 7:43 | https://www.youtube.com/watch?v=ai4YdLiCGNM |
| 13 | ISO/IEC 21838 | 10:00 | https://www.youtube.com/watch?v=aux_zcK7XSI |
| 14 | Reasoning with the Information Artifact Ontology | 7:47 | https://www.youtube.com/watch?v=sTx_rRWmTqE |
| 15 | BFO 2020 Temporalized Relations | 34:10 | https://www.youtube.com/watch?v=fkkWkTIxrNQ |
| 16 | ISO/IEC 21838 | 1:32:41 | https://www.youtube.com/watch?v=_0masZPGLb0 |
| 17 | What problem with OWL is BFO-2020 trying to solve | 28:04 | https://www.youtube.com/watch?v=IDs7Pthdows |
| 18 | Ontologies for Space and Ground Systems | 29:05 | https://www.youtube.com/watch?v=x3ugXHOyLLw |
| 20 | BFO JOWO Tutorial Part 2 | 1:10:53 | https://www.youtube.com/watch?v=wh_KZGXc1Es |
| 21 | BFO JOWO Tutorial Part 1 | 23:27 | https://www.youtube.com/watch?v=VYDe09TOw2M |
| 22 | Introduction to Basic Formal Ontology (September 2019) | 8:51 | https://www.youtube.com/watch?v=p0buEjR3t8A |
| 23 | Ontology as Product-Service System: A Study of GO, BFO and DOLCE | 11:29 | https://www.youtube.com/watch?v=XTVR7k63_VA |
| 24 | BFO Tutorial (2019). Part 5: BFO as Top-Level Ontology | 21:16 | https://www.youtube.com/watch?v=ZMUM1z2Zi9c |
| 25 | BFO Tutorial (2019). Part 6: Temporalized Relations in BFO ISO | 21:55 | https://www.youtube.com/watch?v=8-dGGDQ7qCw |
| 26 | BFO Tutorial (2019). Part 4: Sites, Boundaries, Objects | 19:45 | https://www.youtube.com/watch?v=GJJcu0UKQyo |
| 27 | BFO Tutorial (2019). Part 3: Qualities, Dispositions, Diseases | 24:37 | https://www.youtube.com/watch?v=2UmKWQ-fH4s |
| 28 | BFO Tutorial (2019). Part 2: Why Ontologies Fail | 39:43 | https://www.youtube.com/watch?v=w5d5KmBqw3w |
| 29 | BFO Tutorial (2019). Part 1: Introduction to BFO ISO | 41:11 | https://www.youtube.com/watch?v=muafRW0bXgw |
| 30 | Basic Formal Ontology Applied to the Ontology of Language. With a coda on the Turing Test | 39:42 | https://www.youtube.com/watch?v=Y3btP1InPZY |
| 31 | IOF: Draft BFO Formalization Proposal. 1-25-2019 | 31:06 | https://www.youtube.com/watch?v=ZJgE-O2iREM |
| 36 | How BFO Deals with Data from Multiple Contexts | 16:31 | https://www.youtube.com/watch?v=K9AsCDBRJpM |
| 37 | Why Do We Need Upper-Level Ontologies? | 20:47 | https://www.youtube.com/watch?v=sjf9zeCh_Sw |
| 38 | Relationships between upper-level ontologies | 1:02:25 | https://www.youtube.com/watch?v=gJxfZ3cq5jE |
| 39 | Functions, Dispositions and Capabilities (2017) | 31:15 | https://www.youtube.com/watch?v=lIPg2bGJSzE |
| 40 | Are there Capabilities on Mars? | 1:30:51 | https://www.youtube.com/watch?v=Lo7iPP2wKgw |
| 41 | Introduction to BFO and to the Industrial Ontologies Foundry | 47:16 | https://www.youtube.com/watch?v=fJ4uW7PK5cI |
| 42 | Building Ontologies: An Introduction for Engineers (Part 2) | 53:01 | https://www.youtube.com/watch?v=8vdUUhF4JdE |
| 43 | Building Ontologies: An Introduction for Engineers (Part 1) | 51:30 | https://www.youtube.com/watch?v=HDARyJBvnuc |
| 44 | Building Ontologies: An Introduction for Engineers (Part 2) | 1:44:30 | https://www.youtube.com/watch?v=Gh0f2Us0hr0 |
| 45 | Building Ontologies: An Introduction for Engineers (Part 1) | 54:17 | https://www.youtube.com/watch?v=iTNQYyh88-Y |
| 46 | Introduction to Basic Formal Ontology (2015): Part One | 7:48 | https://www.youtube.com/watch?v=IMCBON2me3Y |
| 47 | Introduction to Basic Formal Ontology (2015): Part Two | 1:44:29 | https://www.youtube.com/watch?v=bGPVCkuKTo4 |
| 48 | Tutorial: Introduction to Basic Formal Ontology 2.0 (2015) | 54:16 | https://www.youtube.com/watch?v=Yl6_M1sQEAQ |
| 49 | Introduction to Basic Formal Ontology (BFO) 2012 | 7:14 | https://www.youtube.com/watch?v=FjOgoKvNNMM (BAD QUALITY) |
| 50 | Part1: Changes in BFO 2.0, by BarrySmith | N/A | N/A |
| 51 | Aboutness | 21:44 | https://www.youtube.com/watch?v=PBKsupBquok |