Man has thinking and reasoning ability as created by God. Most of the present generation do not think much for themselves but most follow a minority who do the thinking for them and create a 'concensus'. Finality of human reason idea still has many followers, even if interspersed with post-modern rejection of absolutes to suit practice.
The impossibility of the Supremacy of Reason.
The only real alternative to acknowledging God as the Creator of all and final authority is the despair of meaninglessness. When God is ignored, there is an absence of external test of the reliability of human reason outside of man himself. Supremacy of human reason position requires several unreasonable assumptions at its starting point and therefore is inherently self-contradictory. These irrational assumptions include: that man is not a creature dependent on his Creator for knowledge; that man is not a sinful creature whose reasoning processes are warped. The faith of the atheistic rationalist is in deified man and the unproven religious tenets of his creed are: man evolved from nothing; that his reasoning ability, though evolved from nothing, is reliable. Use of reason only follows these unreasonable assumptions.
Why Rationalism Has to Begin with Absurdity.
Because it isn't true and man is a dependent creature - Gen.3:4-6. Sin is irrational. Biblical concept of foolishness (Ps.53:1; 94:8-11; Luke 11:40; 12:20). Rationalism an expression of the absurdity of sin.
The Rationalist's Foolishness Not to Be Pandered To.
The demand for proof not to be acceded to. The truth of God rejected is due to sin, not lack of clarity of Divine testimony. Rationalist not to be allowed off the starting line of their absurd assumptions about themselves. Rationalism means meaninglessness of our existence and of concepts of right/wrong, order/confusion, happiness/misery, progress/regression. Emptiness of atheists' defences against despair – collective opinion and collective progress. The irrationality of rationalists to be squarely confronted.
See also the address 'Dawkins' Delusion' and the link below on 'Postmodernism: What is it?'