One need only open the eyes to see that the conquests of industry which have enriched so many practical men would never have seen the light, if these practical men alone had existed and if they had not been preceded by unselfish devotees who died poor, who never thought of utility, and yet had a guide far other than caprice. — H. POINCARE
I. The fallacy of non-experimental judgments, in matters of heredity and development.

II. The fallacy of attributing to one cause what is due to many causes.

III. The fallacy of concluding that because one factor plays a role, another does not; the fallacy of drawing negative conclusions from positive observations.

IV. The fallacy that the characteristics of organisms are divisible into two distinct classes; one due to heredity, the other to environment.

Blog Editorโ€™s Note: I can find no reference to V or VI.

VII. The fallacy of basing conclusions on implied premises that when explicitly stated are rejected. Many premises influencing reasoning are of this hidden, unconscious type. Such ghostly premises largely affect biological reasoning on the topics here dealt with; they underlie several of the fallacies already stated, and several to come.

VIII. The fallacy that showing a characteristic to be hereditary proves that it is not alterable by the environment.

IX. The fallacy that showing a characteristic to be altered by the environment proves that it is not hereditary. It appears indeed probable, from the present state of knowledge and the trend of discovery, that the following sweeping statements will ultimately turn out to be justified:

(1) All characteristics of organisms may be altered by changing the genes; provided we can learn how to change the proper genes.
(2) All characteristics may be altered by changing the environmental conditions under which the organism develops; provided that we learn what conditions to change and how to change them.
(3) Any kind of change of characteristics that can be induced by altering genes, can likewise be induced (if we know how) by altering conditions. (This statement is open to more doubt than the other two; but it is likely eventually to be found correct.)
X. The fallacy that since all human characteristics are hereditary, heredity is all-important in human affairs, environment therefore unimportant.

XI. The fallacy that since all important human characteristics are environmental, therefore environment is all-important, heredity unimportant, in human affairs. — H. S. JENNINGS

Facts cannot be explained by a hypothesis more extraordinary than the facts themselves; and of various hypotheses the least extraordinary must be adopted. — C. S. PIERCE
Somebody was saying to Picasso that he ought to make pictures of things the way they are — objective pictures. He mumbled that he wasn’t quite sure what that would be. The person who was questioning him produced a photograph of his wife from his wallet and said, “There, you see, that is a picture of how she really is.” Picasso looked at it and said, “She is rather small, isn’t she? And flat?” — GREGORY BATESON
The price of anything is the amount of life you exchange for it. — HENRY DAVID THOREAU
Your days are short here; this is the last of your springs. And now in the serenity and quiet of this lovely place, touch the depths of truth, feel the hem of Heaven. You will go away with old, good friends. And don’t forget when you leave why you came. — ADLAI STEVENSON II
Who do you think you are? — PETE WEBER
For the believer there are no questions; for the non-believer there are no answers. — REBBE OF KOTZK