1) Saying that you can reach objective conclusions for what actions you can take purely based on rationality, without making axiomatic assumptions, has all the

1) Saying that you can reach objective conclusions for what actions you can take purely based on rationality, without making axiomatic assumptions, has all the same problems as doing so for mathematical theorems. Objective theories for how to act (including morality), requires that all subjects that could possibly be covered by the theories are 100% in agreement with all axioms. Also, all theory on top of the axioms must be 100% stringent. 2) I think you take the argument the wrong way. Our ideologies tend to influence both what we perceive as rational as well as how important it is for us that something is rational (as opposed to socially acceptable, comfortable, self-serving or a number of other metrics we can use to measure the value of the "something") 3) Rationalism is a well documented ideology (see my other post).