Thinking is an essentially human activity occurring in two basic forms. We may
think in order to attain knowledge of what is, must, or may be the case; we
also may think with a view to making up our mind about what we will or will not
do. Following Aristotle, these two forms of thought may be called,
respectively, contemplation and deliberation.
Both forms may e carried on well or badly, successfully or unsuccessfully,
intelligently or stupidly. When contemplation is successful, it terminates in a
conclusion; successful deliberation terminates in a decision or
resolution.
The form of reasoning involved in contemplation may be called
theoretical, and the form involved in deliberation may be called
practical. Obviously, our day-by-day reasoning in ordinary life is an untidy mixture of
both these basic forms.
Less generally, thinking is commonly understood as a largely covert activity,
something done mainly in foro interno . This activity is also conceived
of as intentional in Franz Brentano's sense of "being directed towards an
object". This object (or subject) of our thinking may be either abstract
or concrete. In thinking about these various objects, we are also
necessarily thinking something about them. We think of them as having various
features, as doing something or other, or as being related in this or that way
to other things of various sorts. Our specific thoughts have contents as
well as objects.
Another distinctive feature of particular thoughts is that the language used to
describe them is nonextensional in a rich sense that is commonly called
intentional.
Thoughts involved in both contemplation and deliberation have the following basic features:
Traditional theories
According to the Platonist, thinking is either a dialogue in the soul
involving mental words that refer to Forms and , possibly, to individuals or a
spiritual activity of inspecting or recollecting Forms and discerning their
natures and interrelations.
According to Aristotelianism, thinking is an act of the intellect in which a thing's essence, or intelligible form, actually qualifies the intellect; to think about humanity is for one's intellect to be informed by - literally, to share - the essence humanity.
For conceptualists (rationalists, Kant) thinking is an activity of bringing concepts or ideas before the mind, these being either innate and applicable to the world in virtue of God's grace (Leibniz, Descartes) or else formed by abstraction from sense experiences and thus actually sharing the abstract features of those experiences (Locke).
For imagists (Berkeley, Hume) thinking is basically a sequence of episodes involving images; these images are tied to certain "habits", which are the inveterate tendencies of the mind to move from one image to another. To think about triangularity is to imagine some particular triangle while disposed to pass on to other images "of the same sort".
According to the psychological nominalist (Hobbes) thinking is literally a dialogue in the soul (or better in the head) involving the use of verbal images, or mental words, which denote things or classes of things. A complete thought is a mental utterance of a sentence.
According to behaviorism, thinking is either thoughtful overt speech or a changing series of dispositions to behave intelligently that the agent can at any time avow.
The analogy theory: Silent thought need not be inner speech, but it may
still be an activity that is at least formally analogous to speech. In what
sense "formally analogous"? In the sense in which chess played with pennies and
nickels is formally analogous to chess played with standard pieces.
While the thought p is empirically different from the act of saying that p, it
may still be regarded as formally the same: both are activities that conform to
the same principles and have many of the same implications (= formal identity
among empirically different
activities).
