“A knowledge of the construction of the heavens has always been the ultimate object of my observations…”

The Philosophy of Physical Science (1938)
Context: Let us suppose that an ichthyologist is exploring the life of the ocean. He casts a net into the water and brings up a fishy assortment. Surveying his catch, he proceeds in the usual manner of a scientist to systematise what it reveals. He arrives at two generalisations: No sea-creature is less than two inches long. (2) All sea-creatures have gills. These are both true of his catch, and he assumes tentatively that they will remain true however often he repeats it.
In applying this analogy, the catch stands for the body of knowledge which constitutes physical science, and the net for the sensory and intellectual equipment which we use in obtaining it. The casting of the net corresponds to observation; for knowledge which has not been or could not be obtained by observation is not admitted into physical science.
An onlooker may object that the first generalisation is wrong. "There are plenty of sea-creatures under two inches long, only your net is not adapted to catch them." The icthyologist dismisses this objection contemptuously. "Anything uncatchable by my net is ipso facto outside the scope of icthyological knowledge. In short, what my net can't catch isn't fish." Or — to translate the analogy — "If you are not simply guessing, you are claiming a knowledge of the physical universe discovered in some other way than by the methods of physical science, and admittedly unverifiable by such methods. You are a metaphysician. Bah!"

Speech at Bristol on declining the poll (9 September 1780)
1780s

In a 1978 interview with John S. Friedman, published in The Paris Review 26 (Spring 1984); and in Elie Wiesel : Conversations (2002) edited by Robert Franciosi, p. 87
Context: Miracles in mysticism don't occupy such an important place. It's metaphor, for the peasants, for the crowds, to impress people. What does mysticism really mean? It means the way to attain knowledge. It's close to philosophy, except in philosophy you go horizontally while in mysticism you go vertically. You plunge into it. Philosophy is a slow process of logic and logical discourse: A bringing B bringing C and so forth. In mysticism you can jump from A to Z. But the ultimate objective is the same. It's knowledge. It's truth.

The Philosophy of Physical Science (1938)
Context: For the truth of the conclusions of physical science, observation is the supreme Court of Appeal. It does not follow that every item which we confidently accept as physical knowledge has actually been certified by the Court; our confidence is that it would be certified by the Court if it were submitted. But it does follow that every item of physical knowledge is of a form which might be submitted to the Court. It must be such that we can specify (although it may be impracticable to carry out) an observational procedure which would decide whether it is true or not. Clearly a statement cannot be tested by observation unless it is an assertion about the results of observation. Every item of physical knowledge must therefore be an assertion of what has been or would be the result of carrying out a specified observational procedure. <!-- p. 9

Astronomical Observations relating to the Construction of the Heavens... (1811)
Context: It will be necessary to explain the spirit of the method of arranging the observed astronomical objects under consideration in such a manner, that one shall assist us to understand the nature and construction of the other. This end I propose to obtain by assorting them into as many classes as will be required to produce the most gradual affinity... and it will be found that those contained in one article, are so closely allied to those in the next, that there is perhaps not so much difference between them... as there would be in an annual description of the human figure were it given from the birth of a child till he comes to be a man in his prime.<!-- p. 270-271

Book III, Ode 29, lines 69–72.
Imitation of Horace (1685)
Context: Be fair, or foul, or rain, or shine,
The joys I have possessed, in spite of fate, are mine.
Not heaven itself upon the past has power;
But what has been, has been, and I have had my hour.

Hyperion
Original: (de) Immerhin hat das den Staat zur Hölle gemacht, daß ihn der Mensch zu seinem Himmel machen wollte.

Source: Watchmen

Julien Levy exhibition catalog (April 1945)