All philoso­phies stand on choic­es that can­not be jus­ti­fied by proof. Any ama­teur Socrates can demon­strate that I can’t prove that two and two are four, or that free­dom is desir­able, or even that I exist. Ulti­mate­ly, ideas, no mat­ter how pas­sion­ate­ly held, rest on assump­tions that can­not be known with absolute cer­tain­ty. It does not fol­low from this that we should avoid act­ing on sig­nif­i­cant assump­tions, or that we should aban­don the analy­sis of ideas. If I’m stand­ing in the mid­dle of the street, and see a twelve-ton truck hurtling in my direc­tion, I don’t stand there, par­a­lyzed by epis­te­mo­log­i­cal uncer­tain­ty. I jump out of its way. Lat­er, seat­ed on a com­fort­able couch, with a cold beer in my hand, I might indulge in the lux­u­ry of reflect­ing that the truck may have been an illu­sion, or that I can­not prove with cer­tain­ty that being hit by a truck is worse than not being hit by a truck. All of us must choose our basic assump­tions, either in a con­scious process, guid­ed by rea­son, or uncon­scious­ly. Read more »