“Development of Western Science is based on two great achievements, the invention of the formal logical system (in Euclidean geometry) by the Greek philosophers, and the discovery of the possibility to find out causal relationships by systematic experiment (Renaissance). In my opinion one has not to be astonished that the Chinese sages have not made these steps. The astonishing thing is that these discoveries were made at all.”

The Philosophy of Space and Time (1928, tr. 1957)

On his years of research in developing the electric light bulb, as quoted in "Talks with Edison" by George Parsons Lathrop in Harper's magazine, Vol. 80 (February 1890), p. 425.
Context: During all those years of experimentation and research, I never once made a discovery. All my work was deductive, and the results I achieved were those of invention, pure and simple. I would construct a theory and work on its lines until I found it was untenable. Then it would be discarded at once and another theory evolved. This was the only possible way for me to work out the problem. … I speak without exaggeration when I say that I have constructed 3,000 different theories in connection with the electric light, each one of them reasonable and apparently likely to be true. Yet only in two cases did my experiments prove the truth of my theory. My chief difficulty was in constructing the carbon filament.... Every quarter of the globe was ransacked by my agents, and all sorts of the queerest materials used, until finally the shred of bamboo, now utilized by us, was settled upon.

On the Greeks, in Ch. 1
The Greek Way (1930)

At [[wikipedia:Liberal International Congress|

As quoted in Nuclear Principles in Engineering (2005) by Tatjana Jevremovic, p. 397

Source: The Creative Process, 1958, p. 97 Partly cited in: Daniel C. Schlenof. " 50 Years Ago: Greatest Scientific Discovery is Science Itself http://www.scientificamerican.com/article/50-100-150-scientific-creativity/," in Scientific American, Aug. 18, 2008.
Context: The most remarkable discovery made by scientists is science itself. The discovery must be compared in importance with the invention of cave-painting and of writing. Like these earlier human creations, science is an attempt to control our surroundings by entering into them and understanding them from inside. And like them, science has surely made a critical step in human development which cannot be reversed. We cannot conceive a future society without science. I have used three words to describe these far - reaching changes : discovery, invention and creation. There are contexts in which one of these words is more appropriate than the others.

The Alchemy of Finance: Reading the mind of the Market (1987)

Fischerisms (1944)

Source: Realistic models in probability (1968), p. 1