is this book a valid (alternative/substitute) for LR and AR books?

spittingnickels

have you ever heard an lsat prepbook describe a negative sufficient condition as a "denial of the antecedent" or an illegal negation described as "affirmation of the consequent"? Ever heard a book mention the latin modus tollens? ponens?

i have not. ever.

the lsat prep books seem to give these concepts different names and designations. However, as i got more interested in conditional logic and formal logic concepts (as a result of lsat studying), i stumbled upon an old book called "A System of Logic" by John Stuart Mill (1843). Mill's book seems to take a look at LSAT logic concepts (provided by the lsat prepbooks ) in a much more formal way, giving the concepts more complicated names, introducing different symbols for propositional statements etc.

my question is this : do the lsat prep books SIMPLIFY mill's book? or is mill's book a more THOROUGH version of the lsat prepbooks? furthermore, could mill's book be used as a complete substitute to some of the lsat prepbooks, helping students save money on prepbooks and ultimately providing a better logical foundation than the prepbooks could provide anyway?

let me know what you think, thanks.

Cant Get Right

I have not read "A System of Logic," but I trust it is comprehensive and wholly accurate. Mill ranks among the likes of Aristotle and Bertrand Russell as far as great thinkers who've contributed to Logic. He is widely considered the greatest intellect of his era, is absolutely worthwhile to read, and many of his works remain highly influential. All of the terminologies you cite are standardized terms used in the more formal, academic field of Logic.

I think the best answer to your first question is that LSAT resources simplify what you're finding in Mill (or Russell, or Aristotle, or Wittgenstein, or many many others). While many resources, including Mill's "A System of Logic," could be substituted for a lot of the more formal aspects of LR, particularly, I'm not sure that's going to be the most effective way to study. It would be cheaper and absolutely give you solid logical foundations, but it would not be targeted to the specific purposes of the LSAT. The LSAT is not a logic test. It's a test that requires some functional knowledge of basic logical relationships, but that's really as deep as it goes. So studying really formalized logic is going to take you so much deeper than what will be practicable for application on the LSAT.

I think studying formal logic is great for its own sake, and just to become a more intelligent person. But if your goal is just to effectively study for the LSAT, I'd recommend keeping it as simple as you can.