But in this case Russell was completely wrong because he interprets Descartes' cogito as a syllogism whereas it is a performative statement. Descrates' is only establishing that it's self-evident for himself that he exists, and not to assert to anyone external that he or his thoughts exist.
Thinking these thoughts however (from a pov of some subject) is not a "mere existence of thoughts". This imo is a classic analytic/positivistic language game.
(I jest, you're preaching to the choir, i.e. a first year philosophy degree drop-out who switched to do computer science to avoid having these arguments)
