A Few Quotes from Babbage's Autobiography

by Martin F. Johansen, 2013

Here are a few selected quotes from Babbage's Passages from the Life of a Philosopher published in 1864. I have placed some remarks in square brackets.

On Method

"It appeared to me that the highest exercise of human faculties consisted in the endeavour to discover those laws of thought by which man passes from the known to that which was unknown. It might with propriety be called the philosophy of invention. During the early part of my residence in London, I commenced several essays on Induction, Generalization, Analogy, with various illustrations from different sources." –p. 428

On Language

"I have invented and brought to maturity a system of signs for the explanation of machinery, which I have called Mechanical Notation, by means of which the drawings, the times of action, and the trains for the transmission of force, are expressed in a language at once simple and concise. Without the aid of this language I could not have invented the Analytical Engine; nor do I believe that any machinery of equal complexity can ever be contrived without the assistance of that or of some other equivalent language." –p. 104
"By its application [of the Machanical Notation] to geometrical drawing it has given us a new demonstrative science, namely, that of proving that any given machine can or cannot exist; and if it can exist, that it will accomplish its desired object." –p. 104
"By the aid of the Mechanical Notation, the Analytical Engine became a reality: for it became susceptible of demonstration." –p. 113

On the Analytical Engine

"The Analytical Engine consists of two parts:—

1st. The store in which all the variables to be operated upon, as well as all those quantities which have arisen from the result of other operations, are placed.

2nd. The mill into which the quantities about to be operated upon are always brought.

Every formula which the Analytical Engine can be required to compute consists of certain algebraical operations to be performed upon given letters, and of certain other modifications depending on the numerical value assigned to those letters." –p. 117

On Computer Science

"The Analytical Engine is therefore a machine of the most general nature. Whatever formula it is required to develop, the law of its development must be communicated to it by two sets of cards. When these have been placed, the engine is special for that particular formula. The numerical value of its constants must then be put on the columns of wheels below them, and on setting the Engine in motion it will calculate and print the numerical results of that formula." –p. 118
"I considered that a machine to execute the mere isolated operations of arithmetic would be comparatively of little value, unless it were very easily set to do its work, and unless it executed not only accurately, but with great rapidity, whatever it was required to do." –p. 42-43
"It is impossible to construct machinery occupying unlimited space; but it is possible to construct finite machinery, and to use it through unlimited time." –p. 126
"These two memoirs [Passages from the Life of a Philosopher and Sketch of the Analytical Engine] taken together furnish, to those who are capable of understanding the reasoning, a complete demonstration—That the whole of the developments and operations of analysis are now capable of being executed by machinery." –p. 136

Copyright © 2013, Martin F. Johansen