George Boole Quotes

A successful attempt to express logical propositions by symbols, the laws of whose combinations should be founded upon the laws of the mental processes which they represent, would, so far, be a step towards a philosophical language.

The general laws of Nature are not, for the most part, immediate objects of perception. They are either inductive inferences from a large body of facts, the common truth in which they express, or, in their origin at least, physical hypotheses of a causal nature serving to explain phenomena with undeviating precision, and to enable us to predict new combinations of them. They are in all cases, and in the strictest sense of the term, probable conclusions, approaching, indeed, ever and ever nearer to certainty, as they receive more and more of the confirmation of experience. But of the character of probability, in the strict and proper sense of that term, they are never wholly divested. On the other hand, the knowledge of the laws of the mind does not require as its basis any extensive collection of observations. The general truth is seen in the particular instance, and it is not confirmed by the repetition of instances.

It is not of the essence of mathematics to be conversant with the ideas of number and quantity.

I presume that few who have paid any attention to the history of the Mathematical Analysis, will doubt that it has been developed in a certain order, or that that order has been, to a great extent, necessary -- being determined, either by steps of logical deduction, or by the successive introduction of new ideas and conceptions, when the time for their evolution had arrived.

The principles of the theory of probabilities [cannot] serve to guide us in the election of... [scientific] hypotheses.

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.

A distinguished writer (Siméon Denis Poisson) has thus stated the fundamental definitions of the science:

[Boole's apparent goal was to] unfold the secret laws and relations of those high faculties of thought by which all beyond the merely perceptive knowledge of the world and of ourselves is attained or matured, is a object which does not stand in need of commendation to a rational mind.

You will feel interested to know the fate of my mathematical speculations in Cambridge. One of the papers is already printed in the Mathematical Journal. Another, which I sent a short time ago, has been very favourably received, and will shortly be printed together with one I had previously sent.

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.

That to the existing forms of Analysis a quantitative interpretation is assigned, is the result of the circumstances by which those forms were determined, and is not to be construed into a universal condition of Analysis. It is upon the foundation of this general principle, that I purpose to establish the Calculus of Logic, and that I claim for it a place among the acknowledged forms of Mathematical Analysis, regardless that in its object and in its instruments it must at present stand alone.

It is not possible, I think, to rise from the perusal of the arguments of Clark and Spinoza without a deep conviction of the futility of all endeavors to establish, entirely à priori, the existence of an Infinite Being, His attributes, and His relation to the universe. The fundamental principle of all such speculations, viz. that whatever we can clearly conceive, must exist, fails to accomplish its end, even when its truth is admitted. For how shall the finite comprehend the infinite? Yet must the possibility of such conception be granted, and in something more than the sense of a mere withdrawal of the limits of phænomal existence, before any solid ground can be established for the knowledge, à priori, of things infinite and eternal.

I have endeavoured, in the following treatise, to convey as complete an account of the present state of knowledge on the subject of Differential Equations, as was consistent with the idea of a work intended, primarily, for elementary instruction. It was my object, first of all, to meet the wants of those who had no previous acquaintance with the subject, but I also desired not quite to disappoint others who might seek for more v advanced information. These distinct, but not inconsistent - aims determined the plan of composition.

The last subject to which I am desirous to direct your attention as to a means of self-improvement, is that of philanthropic exertion for the good of others. I allude here more particularly to the efforts which you may be able to make for the benefit of those whose social position is inferior to your own. It is my deliberate conviction, founded on long and anxious consideration of the subject, that not only might great positive good be effected by an association of earnest young men, working together under judicious arrangements for this common end, but that its reflected advantages would overpay the toil of effort, and more than indemnify the cost of personal sacrifice. And how wide a field is now open before you! It would be unjust to pass over unnoticed the shining examples of virtues, that are found among tho poor and indigent There are dwellings so consecrated by patience, by self-denial, by filial piety, that it is not in the power of any physical deprivation to render them otherwise than happy. But sometimes in close contiguity with these, what a deep contrast of guilt and woe! On the darker features of the prospect we would not dwell, and that they are less prominent here than in larger cities we would with gratitude acknowledge; but we cannot shut our eyes to their existence. We cannot put out of sight that improvidence that never looks beyond the present hour; that insensibility that deadens the heart to the claims of duty and affection; or that recklessness which in the pursuit of some short-lived gratification, sets all regard for consequences aside. Evils such as these, although they may present themselves in any class of society, and under every variety of circumstances, are undoubtedly fostered by that ignorance to which the condition of poverty is most exposed; and of which it has been truly said, that it is the night of the spirit,—and a night without moon and without stars. It is to associated efforts for its removal, and for the raising of the physical condition of its subjects, that philanthropy must henceforth direct her regards. And is not such an object great 1 Are not such efforts personally elevating and ennobling? Would that some part of the youthful energy of this present assembly might thus expend itself in labours of benevolence! Would that we could all feel the deep weight and truth of the Divine sentiment that " No man liveth to himself, and no man dieth to himself.

The following work is not a republication of a former treatise by the Author, entitled, "The Mathematical Analysis of Logic." Its earlier portion is indeed devoted to the same object, and it begins by establishing the same system of fundamental laws, but its methods are more general, and its range of applications far wider. It exhibits the results, matured by some years of study and reflection, of a principle of investigation relating to the intellectual operations, the previous exposition of which was written within a few weeks after its idea had been conceived.