chapters 10-13

### Deductive inference

the act by which the mind establishes a connection between the antecedent and the consequent.

### Syllogism

a group of propositions in orderly sequence, one of which (the consequent) is said to be necessarily inferred from the others (the antecedent).

### First Corollary

If the syllogism is valid and the consequent is false, then the antecedent must be false.

### Second Corollary

In a valid syllogism with a true consequent, the antecedent is not necessarily true.

### The Principle of Reciprocal Identity

Two terms that are identical with a third term are identical to each other.

### The Principle of Reciprocal Non-Identity

Two terms, one of which is identical with a third term and the other of which is nonidentical with that third term, are nonidentical to each other.

### The Dictum de Omni

What is affirmed universally of a certain term is affirmed of every term that comes under that term

### The Dictum de Nullo

What is denied universally of a certain term is denied of every term that comes under that term.

### Terminological Rules

I. Ther must be three and only three terms. II.The middle term must not occur in the conclusion

### Quantitative Rules

III. If a term is distributed in the conclusion, then it must be distributed in the premise. IV. The middle term must be distributed at least once.