Can he back up his opinions with any facts? E.g. what does he think is good about solids, circ, etc? Has he seen any research supporting his position? My guess would be no. You, on the other, can support your views based on real facts and research and can likely articulate meaningful reasons for your views. Tell him that you are more than open to discussing these matters with him, but he has to come to the table with more than random, biased, uninformed opinions (sorry if that sounds harsh--don't mean it that way). Definitely allow him to make his case as well. It is preferable to decide these things together (he certainly should have a say in how you raise your child), but the decisions should be informed ones.