p. 163 quote from Spinoza Ethica (appendix)
Men think themselves free, because they are conscious of their volitions and of their desires and are oblivious to the causes which dispose them to desire and to will.
Swiftly the head-mass becomes an enchanted loom where millions of flashing shuttles weave a dissolving pattern, always a meaningful pattern though never an abiding one; a shifting harmony of sub-patterns. Now as the waking body rouses, subpatterns of this great harmony of activity stretch down into the unlit tracks of the stalk-piece of the scheme. Strings of flashing and travelling sparks engage the lengths of it. This means that the body is up and rises to meet its waking day.
The mind is a something with such manifold variety, such fleeting changes, such countless nuances, such wealth of combinations, such heights and depths of mood, such sweeps of passion, such vistas of imagination, that the bald submission of some electrical potentials recognizable in nerve-centers as correlative to all these may seem to the special student of mind almost derisory. It is, further, more than mere lack of corresponding complexity which frustrates the comparison.
If as you say thoughts are an outcome of the brain we as students using the energy-concept know nothing of it; as followers of natural science we know nothing of any relation between thoughts and the brain, except as a gross correlation in time and space. In some ways this is embarrassing for biology.