Excerpts from Deliverance from Error, Al-Ghazali

TYPES OF SEEKING TRUTH

"various seekers (after truth) as comprising four groups:

1) The Theologian (mutakallimun), who claim they are the exponents of thought and intellectural speculation

2) the Batiniyyah (Shi'a), who consider that they, as the party of authoritative instruction (ta3lim) alone derive the truth from the infallible imam

3) the Philosophers, who regard themselves as the exponents of logic and demonstrative proof

4) the Sufis / Mystics who claim that they alone enter into the 'presence' (of God) and possess vision and intuitive understanding"

...

TYPES OF KNOWING TRUTH

Certainty (yaqeen) reached by demonstration is "knowledge" (3ilm)

actual acquaintance with that state is "immediate experience" (dhawq)

The acceptance of it as probable from hearsay and trial (or observation) is "faith" (imaan)

...

RISKS OF KNOWLEDGE

Satan,to impress you, rehearses the excellence of knowledge, the high rank of scholar and the Traditions (hadith) about knowledge from the Prophet and others. He thus diverts your attention from sayings of the Prophet (s.a.a.s) such as the following:

• Whoever increases in knowledge and does not increase in guidance, only increases in distance from God
• the most severe punishment on the Day of Resurrection is that of the scholar to whom God gave no benefit from his knowledge
• O God I take refuge with You from knowledge which does not benefit me, from the heart which does not humble itself, from the act which is not lifted up, and from the prayer (dua) which is not heard
• During my night-journey I passed some groups of people whose lips were cut by fiery scissors and I said to them, "Who are you?" and they replied "We used to command others to do good and yet ourselves did not do it, and to prohibit others from doing evil and yet ourselves did it"