David Hume

Recurring themes

• a compulsion to locate the exact moment where legitimate inference tips into unjustified assumption, and to sit there uncomfortably rather than paper over it
• the suspicion that familiarity is a cognitive trick — that custom disguises itself as understanding and the more habitual a belief, the more epistemically naked it actually is
• a recurring drive to show that human intellectual ambition always terminates at a wall, and that the honest response to that wall is not to pretend it isn't there but to map its exact dimensions
• the uneasy recognition that the tools we use to justify knowledge — reason, experience, analogy — cannot themselves be justified by those same tools without circularity

Mental models

• Hume's Fork — the analytic/synthetic distinction deployed as a sorting machine to quarantine all meaningful empirical claims from rational demonstration, then used to show that causation falls on the wrong side
• Infinite regress of justification — every foundation for knowledge is shown to require a further foundation, applied relentlessly to reveal that the chain of 'why' questions has no terminus
• The concealment effect of habit — familiarity is modeled as an epistemic analgesic that raises the threshold for noticing foundational gaps, applied specifically to billiard-ball causation and bread nutrition as test cases
• Reduction to the arbitrary — any inference made without experience is shown to be selection among equally conceivable alternatives with no principle of selection, used to demonstrate that a priori causal reasoning is not reasoning at all but invention

Intellectual DNA

• Pyrrhonian skepticism — the habit of following each apparent resolution back to a deeper uncertainty, and treating the proliferation of doubt as itself a philosophical method rather than a failure, echoes Sextus Empiricus in structure if not in conclusion
• Lockean empiricism by rejection — the writing inherits Locke's insistence that ideas come from experience but presses past Locke's comfort zone to ask what licenses the move from past experience to future expectation, a question Locke never seriously confronted
• Newtonian modesty — the repeated move of saying science can identify regularities but cannot penetrate to ultimate causes mirrors Newton's 'hypotheses non fingo,' applied now as an epistemological rather than methodological principle
• Berkeley's dissolution strategy — the method of taking an apparently solid concept (causation, necessary connection) and showing it dissolves under inspection into something much thinner, leaving custom and habit where necessity was assumed to live