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A Little Catechism on Logic

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I've been messing around with the concept of writing a set of catechisms on the philosophical sciences as a primer for further study. To get one introduced to the grammar of the discpline. I finished a bit on Logic and wanted to put it out there. Let me know what you think!


Q1: Why should we study logic?

A: We should study logic, first, to have certainty that our beliefs are correct, and, second, to discover new truths from what we already know.

Q2: What is logic?

A: “Logic is the science which directs the mind in the attainment of truth.”

Q3: What is a “science?”

A: We do not use “science” in the modern sense of a “physical science,” such as biology or chemistry, rather a science is “the knowledge of things in connection with their causes.”

Q4: How is logic a science?

A: Logic is a science because it does not only treat the rules of reasoning, but the causes or reasons why those rules work.

Q5: What are the parts of logic?

A: Logic has two parts, Formal Logic/Dialectics, and Material/Critical Logic.

Q6: What is Dialectics?

A: Dialectics studies the way in which our minds reason and, in particular, “the rules to be observed in reasoning or discussing.”

Q7: What is Critical Logic?

A: Critical Logic studies the reliability of our knowledge, especially the question of certainty.


Q8: What is the purpose of Dialectics?

A: Dialectics “teach pupils how to reason correctly themselves, and readily to detect flaws in the false reasonings of others.”

Simple Apprehensions

Q9: What is Simple Apprehension?

A: Simple Apprehension is “the act of perceiving an object intellectually, without affirming or denying anything concerning it.”

Q10: What is the product of Simple Apprehension?

A: Simple Apprehension forms an intellectual image, called a species.

Q11: What is the act of forming this species called?

A: Forming the species is called conception.

Q12: What is the product of this mental conception called?

A: The product of mental conception may be called a “concept, idea, or notion of the object.”

Q13: Why is the term “simple” used?

A: The word “simple” is used to highlight the fact that we are neither affirming or denying anything about the object, rather, we are simply conceiving the idea of the object.

Q14: What is the chief error of students when it comes to thinking about Simple Apprehension?

A: The chief error of students comes in conflating an idea with a phantasm.

Q15: What is a phantasm?

A: A phantasm is that material representation of some object in the brain.

Q16: How does a phantasm differ from an idea?

A phantasm has many details attached to it, whereas the idea is only the object itself.

Q17: Give me an example of the difference between the two.

A: “I intellectually conceive a triangle by apprehending a figure enclosed by three lines and thus having three angles. My notion or idea contains this and nothing more; it is very precise, and every one who conceives a triangle conceives it exactly the same way. But when I imagine a triangle, I cannot help imagining it with sensible material accidents, as being of such or such a size and shape, a foot long at one time, a mile long at another. The picture may be vague, various pictures of triangles may be blended together; but it can never be universal, representing all possible triangles, as my idea does.”

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