Suppose, on the other hand, that it is possible to give good and informed advice on such matters: then surely it would be absurd if there were no knowledge on the basis of which it is possible to give good and informed advice on these matters and if there is some knowledge on the basis of which it is possible to give good advice about such matters, then there must be some people who in fact know how to give good advice on such matters; and if there are some people who know how to give advice on the matters you are meeting to discuss, then necessarily in your own case