For example, 'God is Spirit' is an affirmative proposition; while 'God

is not man' is a negative one.

Propositions, considered merely as sentences, are divided into two

classes, categorical and hypothetical.  The categorical class simply asserts

that the predicate does, or does not, apply to the subject, e.g.:

'The world had an intelligent Maker'.

'Man is not capable of raising himself unassisted from the savage to

the civilised state'.

The hypothetical class makes an assertion under a condition, or with an

alternative, for instance:

'If the world is not the work of chance, it must have had an

intelligent Maker'.

'Either mankind is capable of rising into civilisation unassisted, or

the first beginnings of civilisation must have come from above'

(Archbishop Whately).

Another method of classifying propositions is the following:

Universal --

'All men are mortal'.

Particular --

'Some men are mortal'.

Indefinite --

'Man is mortal'.

Singular --

'Julius Caesar is mortal'.

The signs of a universal proposition are the words 'all', 'no' and

'every'.  The word 'some' indicates the particular, and a proper name

indicates the singular.  The absence of these signs characterizes the

indefinite proposition:

'What is the immediate object of belief in a proposition?  What is the

matter of fact signified by it?  What is it to which, when I assert the

proposition, I give my assent, and call upon others to give theirs?

'One of the clearest and most consecutive thinkers whom this country or

the world has produced, I mean Hobbes, has given the following answer

to this question.  "In every proposition says he, what is signified is

the belief of the speaker that the predicate is a name of the same

thing of which the subject is a name; and if it really is so, the

proposition is true".  Thus the proposition, all men are living beings

(he would say) is true, because living being is the name of everything

of which man is a name.  All men are six feet high, is not true,

because six feet high is not a name of everything of which man is a

Propositions, however, are not always set out as formally as logic

requires.  Usually they take the form of 'propositions considered as

sentences', as indicated a little earlier.  These are compound; the first one

cited includes a series of assertions and inferences from the presence of the

'world' of design and its association with intelligence.  Consequently

Hobbes' rule will only apply when all sentences are reduced to their simplest

forms, as indicated in the five classifications that follow.

Another way of expressing it, is that a proposition consists in

referring something to a class.  Thus, 'man is mortal', according to this

view of it, asserts that the class, 'man', is included in the class 'mortal'.