As opposed to the dismissive attitude about "reductionism" among philosophy's current orthodoxy, a "ruthless reductionism" is alive and thriving in cellular and molecular neuroscience (the mainstream of the current discipline). The experimental practices in this branch of neuroscience contain a response to a common philosophical criticism of reduction, namely, that these sciences can only establish "mere correlations" between cellular/molecular and psychological events. These experimental practice involve directly manipulating either electrophysiological cellular activity or molecular components of sub-cellular and gene expression pathways to elicit specific behavioral effects in alert, awake, behaving animals. I'll illustrate this condition and its importance for explanation and reduction in current mainstream neuroscience by describing recent work on mammals in Eric Kandel's, Alcino Silva's, and William Newsome's laboratories.