[24 June 1915]
As you have guessed, dealing further with the question of the psychological types has not given me any real headaches. I have never been fainthearted or desperate, but in finding similar opposites in the most varied fields I have tried to find the consolation that development is not possible at all without opposites. I have never viewed the problem of the types as the existence of two truths, however, but I have rather envisaged, from the genetic point of view, the existence of two poles between which psychic development occurs.
When I read Bergson’s “Évolution créatrice” [Creative Evolution] two years ago, I tried to draw parallels between the urge toward abstraction and the urge toward feeling- into, on the one hand, and Bergson’s pairs of opposites: plant and animal life on the one side, and intellect and instinct, on the other.61 If life is always built upon the interplay between complementary, yet also diverging, tendencies, why shouldn’t this also be the case in psychology? Like Bergson, I conceived the opposites as springing from a common primordial type that originally united both tendencies in itself.62 As development progresses, everybody is following only one tendency and lets the other atrophy. If opposites develop in this process, it is still their purpose to complement each other. Just as the cycle
61 Bergson explores these branchings of life energy throughout chapter 2 of his book, concluding that “consciousness, after having been obliged, in order to set itself free, to divide organization into two complementary parts, vegetables on one hand and animals on the other, has sought an issue in the double direction of instinct and of intelligence” (Bergson, 1907, p. 185).
62 Bergson speaks of “the dissociation of the primordial tendency into such and such complementary tendencies which create divergent lines of evolution” (ibid., p. 255).