A faculty (habitus) is a more or less efficacious ability (facultas) to act, formed by repeated actions. Faculties are either intellectual or moral: the former strengthen and perfect the powers of the intellect, the latter the powers of the will.
There are five distinct names (they are not distinct kinds) given to our intellectual faculties: intelligence, wisdom, prudence, science, and skill, which in Greek are: nous, sophia, phronesis, episteme, techne.1 Intelligence is the faculty of first principles. Wisdom is knowledge of the most excellent things. Prudence is the faculty of acting with right reason. Science is the faculty of demonstration. Skill is the faculty of producing things with right reason. Philosophy is the whole bundle of these liberal arts, and is commonly defined as “acquisition of the knowledge (cognitio) of human and divine things, which we pursue by the sole power of human reason.” Philosophy is frequently divided into rational philosophy (or logic), natural philosophy, and moral philosophy.2 Logic is the art which directs the mind in its acquisition of knowledge of things, and may also be called science (scientia).3 Others define it as “the art of investigating and expressing truth.”4 The material object of any skill or science is the material which it treats. The formal object is the reason or purpose of treating it. The material object of logic is the intellectual operations. The formal object is to be directed to the discovery of truth. There are two natural faculties of the mind, the understanding and the will. The understanding is the faculty (facultas) which is concerned with getting to know the truth. The will is the faculty (facultas) which seeks good and avoids evil.5
There are three classes of operations in the intellect: (1) apprehension, (2) judgment, and (3) discourse; a twofold division into apprehension and judgment is also possible. Judgments are subdivided into noetic and dianoetic judgments. Hence logic is divided into three parts, defined by the kind of operation each is dealing with.6
CHAPTER 1
On the Divisions of Apprehension
Apprehension is also called perception, concept, notion, intention,1 and idea; the word which signifies it is called a term.
Apprehension is a bare representation of a thing without any opinion (sententia) of the mind, and is either noncomplex, for instance pen, or complex, for instance, pen in the hand.
Judgment is an act of the mind by which it forms an opinion about two ideas. The sign [of a judgment] is a proposition or expression, which is an utterance that affirms or denies something of something; it is also called predication.
Discourse is an act of the mind by which from two or more judgments a third is inferred.
1. Ideas are divided into sensations, imaginations, and pure intellections.2
Sensation is twofold, external and internal. External sensation is “the perception of a corporeal thing impacting the organs of the body.”
Imagination is “the idea of a corporeal thing which is not impacting the body.”
A pure intellection is “any idea which is not reached or grasped by any of the bodily senses.” By intellection we not only discern things which are different from body as well as their modes, but we also attain more accurate ideas of numbers and of shapes which have several parts than those which the senses provide.3
The powers of bodies to excite ideas of “colors, sounds, smells, tastes, heat and cold” are called secondary qualities, or qualities which are sensible in the proper sense that we perceive each of them only by a single sense. Things which are perceived by more than one sense, by both sight and touch, for example, such as extension, figure, position, motion and rest, are primary and true qualities of bodies; hence they have the power to excite ideas of secondary qualities to which there is nothing corresponding in the bodies themselves. There are also two ideas which can be perceived both by internal and by external sense, and these are duration and number.
2. Imagination calls up a rather weak idea of a thing that had been formerly perceived by sense. And the mind can form only images whose elements have all been perceived by sense.
3. There is also an internal sense which above all furnishes pure intellections; this is called consciousness (conscientia) or the power of reflection. This sense affects all the actions, passions, and modes of the mind: namely, judgment, discourse, certainty, doubt, joy, sorrow, desires, aversions, love and hatred, virtues, vices. The more precise and abstract ideas of primary qualities are also attributed to pure intellections. But in truth all ideas arise from reflection or from [an] external sense.4
CHAPTER 25
1. Ideas are either clear or obscure: a clear idea is one which “vividly affects the mind”; an obscure idea is one which affects the mind faintly.
2. Ideas may be proper [ideas] and truly depict the thing put before it or at least represent the appearance (speciem) which nature commonly intended; or they may be analogical [ideas] and exhibit a kind of general and imperfect impression of a thing, not as it is in itself or as it is represented in the common order of nature, but by a kind of analogy with other, very different things which are known by proper ideas. Those who have the use of sight have a proper idea of sight; a blind man has an analogous idea, but he does still have some kind of useful notion of this faculty.
3. Ideas are either simple or complex; a simple idea is a kind of uniform representation not made up of parts that are different from each other.
A complex idea is one “which is made up of dissimilar parts into which it can also be resolved.”
The idea of being is the simplest [idea]; ideas of secondary qualities are also mostly simple, as well as abstract ideas of certain modes of thinking.
4. In respect of their names, ideas are either distinct or confused. A distinct idea is one “which is easily told apart from others.” A confused idea is one “which is not easily told apart from others from which it is thought to be different.”
But perhaps more correctly the name itself or the term which denotes the idea is said to be distinct “when a known and certain complex of ideas is bound together by a name which cannot be altered without our being aware of it”; it is confused when “that complex is not sufficiently certain, so that something may at some point be added or removed [from it] without our noticing.”
5. In respect of their objects, ideas are either of substances or of modes, or of substances together with their modes. A substance is “a being subsisting in itself.” A mode is “a being which inheres in another [being].”
6. Ideas likewise may be real (or true), or they may be fictitious. Real ideas are “ideas which have corresponding objects,” or [ideas] which arise from natural causes following the order of nature. Fictitious [ideas] are “arbitrary conjunctions of ideas not drawn from true things.”
7. Ideas are either adequate or inadequate. Adequate ideas are those “which represent the whole nature of an object,” or at least all of it that we want to conceive in our minds. Such are the complex or combined ideas of modes which the mind assembles in an arbitrary fashion without referring them to an external model; also ideas of modes of thinking or of states of mind. Our ideas of substances are all inadequate.
CHAPTER 3
Abstraction is “the act of the mind by which it directs itself to one or some of the ideas which are contained in a complex [idea] and ignores the rest.” Abstract ideas are ideas which are denoted by names or symbols that signify several things that are similar to each other but which also have some evident differences.6