Over at Neurophilosophy, Mo highlights one of my favorite William James quotes:
The stream of thought flows on; but most of its segments fall into the bottomless abyss of oblivion. Of some, no memory survives the instant of their passage. Of others, it is confined to a few moments, hours or days. Others, again, leave vestiges which are indestructible, and by means of which they may be recalled as long as life endures.
Notice his emphasis on the inherent unknowability of the mind, the way so many of our thoughts and sensations are constantly falling into the “abyss of oblivion”. This was, in part, a reaction to the psychology of the day, which was so eager to measure the mind and quantify our thoughts. James, on the other hand, was convinced that the most interesting aspects of the mind were inherently unmeasurable. As he wrote in his Principles, “It is, in short, the reinstatement of the vague to its proper place in our mental life which I am so anxious to press on the attention.”
And here is how I describe this Jamesian attitude in my book:
James always enjoyed puncturing the pretensions of nineteenth century science. He thought that we should stop thinking of scientific theories as mirrors of nature, what he called “the copy version of truth”. Instead, we should see its facts as tools, which “help us get into a satisfactory relation with experience.” The truth of an idea, James wrote, is the use of an idea, its “cash-value.” Thus, according to the pragmatists, a practical poet could be just as truthful as an accurate experiment. All that mattered was the “concrete difference” an idea produced in our actual lives.
But before he became a philosopher, William James was a psychologist. In 1875, he established one of the world’s first psychological laboratories at Harvard. Though he was now part of the medical school, James had no intention of practicing “brass instrument psychology,” his critical name for the new scientific approach that tried to quantify the mind in terms of its elemental sensations. What physicists had done for the universe, these psychologists wanted to do for our consciousness. Even their vocabulary was stolen straight from physics: thought had a “velocity,” nerves had “inertia,” and the mind was nothing but its “mechanical reflex-actions.” James was contemptuous of such a crude form of reductionism. He thought its facts were useless.
James also wasn’t very good at this new type of psychology. “It is a sort of work which appeals particularly to patient and exact minds,” he wrote in his masterpiece, The Principles of Pscyhology, and James realized that his mind was neither patient nor particularly exact. He loved questions more than answers, the uncertainty of faith more than the conviction of reason. He wanted to call the universe the pluriverse. In his own psychological experiments, James was drawn to the phenomena that this mental reductionism ignored. What parts of our mind cannot be measured?