The Republic by Plato (really anything by him) is surprisingly a decent self-improvement book, at least books I-V, the rest is good if you're interested in metaphysics. What I want to do is ignite in other anons an interest in that subject. Far too many people dismiss it as an out-dated branch no longer worth pursuing. Few people have an interest in it, and even fewer realise it's a subject that encapsulates philosophy itself (i.e. philosophy is a branch of metaphysics, not the other way around).
Self-development should always ultimately lead one to higher levels of thinking. The body reflects the state of the soul. A clean soul is one whose conduct stirs clear of wrong-doing, which then reflects onto the condition of the body: developing a meditation habit leads to more immediate serenity; giving in to anger leads to tremors; etc. These are chemical, bodily reactions. The soul-as-such doesn't 'perceive'. What *is* has influence on what comes into being and ceases to be, not the other way around.
EMENDATION OF THE MIND IS ESSENTIAL. Read these books/texts if you want to elevate towards the highest realm of thinking possible, as a mortal. Far, far superior to that modern gay navel-gazing existentialism BS.
The FUNDAMENTALS:
>On Nature by ParmenidesYou must understand 'esti', BEING, what-is. The further you read, think (your subconscious doing all the work for you), the clearer the relation between being/what-is, God, and YOUR (YES YOU) soul.
>Phaedo>The Republic>Parmenides>TimaeusAll by Plato. Reading this, you'll slowly realise mind IS soul. They're not distinct. Because of conventional, contingent and false notions about the soul, people don't realise you can put the word 'mind' in place of 'soul' in these texts, and it will make more sense.
How does the soul perform its intellectual conduct? The answer is 'by way of dialectic': the soul (i) perceives a problem, (ii) deliberates upon it, speaks to and reasons with itself, (iii) then resolves the problem. Next in line for the fundamentals is Aristotle, the founder of the academic field of logic. Logic is for obvious reasons required in dialectical conduct. His prose is dry and hard, but absolutely essential, so I suggest the following secondary lit for a better understanding:
>AristoPost too long. Click here to view the full text.