11 quotes
The general laws of Nature are not, for the most part, immediate objects of perception.
An Investigation of the Laws of Thought (1854)
For how shall the finite comprehend the infinite?
An Investigation of the Laws of Thought (1854)
It is not of the essence of mathematics to be conversant with the ideas of number and quantity.
An Investigation of the Laws of Thought (1854)
To deduce the laws of the symbols of Logic from a consideration of those operations of the mind which are implied in the strict use of language as an instrument of reasoning.
An Investigation of the Laws of Thought (1854)
That logic, as a science, is susceptible of very wide applications is admitted; but it is equally certain that its ultimate forms and processes are mathematical.
An Investigation of the Laws of Thought (1854)
There is not only a close analogy between the operations of the mind in general reasoning and its operations in the particular science of Algebra, but there is to a considerable extent an exact agreement in the laws by which the two classes of operations are conducted.
An Investigation of the Laws of Thought (1854)
The principles of the theory of probabilities [cannot] serve to guide us in the election of... [scientific] hypotheses.
An Investigation of the Laws of Thought (1854)
That axiom of Metaphysicians which is termed the principle of contradiction and which affirms that it is impossible for anything to possess a quality, and in the same time not to possess it, is a consequence of the fundamental law of thought, whose expression is x²=x.
An Investigation of the Laws of Thought (1854)
A distinguished writer (Siméon Denis Poisson) has thus stated the fundamental definitions of the science
An Investigation of the Laws of Thought (1854)
Probability is expectation founded upon partial knowledge. A perfect acquaintance with all the circumstances affecting the occurrence of an event would change expectation into certainty, and leave neither room nor demand for a theory of probabilities.
An Investigation of the Laws of Thought (1854)
The above interpretation has been introduced, not on account of its immediate value in the present system, but as an illustration of a significant fact in the philosophy of the intellectual powers, viz., that what has commonly been regarded as the fundamental axiom of metaphysics is but the consequence of a law of thought, mathematical in its form.
An Investigation of the Laws of Thought (1854)