In his writing he alludes to unnecessarily complicated reasoning- involving a plenitude of extraneous reasoning, and this has been passed down to us via several others but most recently Lord "Who wanted to sleep with someone else's wife" Bertie Russell. He reiterated the "Occam Razor" approach to reasoning, but he entirely misunderstood William of Occam.
William believed in God, and thought that only by faith alone could you understand this. Therefore he affirmed that everything is derived from God alone, and therefore it unnecessarily complicates to involve other causes.
What Bertrand Russell tried to claim is patently false- the simplest explanation is the best. It is a statement of limited human intellect and mental focus, and our penchant for the simple by collective affirmation and tendency.
Who would believe that Russell coined the term "Occam razor" and spread the thinking about, because he wanted to sleep with someone else's wife? It may seem complicated, but it is in fact, true.