Thomas Henry Huxley

huxley
It is an error to imagine that evolution signifies a constant tendency to increased perfection. That process undoubtedly involves a constant remodeling of the organism in adaptation to new conditions; but it depends on the nature of those conditions whether the direction of the modifications effected shall be upward or downward.
‘The Struggle for Existence in Human Society’ (1888). In Collected Essays (1894), Vol. 9, 199.

Thomas Henry Huxley

huxley
Science commits suicide when it adopts a creed.
Speech at the Museum, South Kensington, on unveiling of a statue of Charles Darwin. Quoted in Herbert Spencer, ‘The Factors of Organic Evolution’ (April/May 1886), The Nineteenth Century, Vol. 19, 770.
Hear hear. Though I don’t think it’s in any danger of doing that.