I agree heartily with your first bit, but not with the last paragraph. It seems to me that fears can be rational or irrational. If the former, they should be respected; if the latter, discussed appropriately in the light of reason. (Yes, DH and I are very nerdy in this respect.) As you say, you can’t decide for other people if something is a good reason or not, but they can, and should.
I had severe PPD after DD’s birth–like, I can’t remember most of her first year except as a vague blur of nonstop suicidal thoughts, illnesses, and screaming/crying on both of our parts. It was
bad. Once we finished out the year of avoidance that my OB wanted us to follow (DD was born via CS, and I needed to heal), DH and I started discussing another baby. I was terrified of having PPD like that again, and of what sort of damage I might do to myself or either kid, especially DD now that she’s more aware. That’s a valid, rational fear: a mom with severe PPD can mean a lot of really bad things. However, I felt like God wanted us to try for another kid, which seemed contradictory. Plus, feelings aren’t facts, and we’re rational beings and expected to behave like rational beings, deciding on actions based on the reason and judgment God gave us, not just on how we feel.
(For example, there were plenty of times in that first year when I felt like I would only be able to stay sane if I went on birth control because I could never, ever go through all that again, but given that I could reason my way to that being wrong, I never went on it.)
As we talked it out, though, we were able to make plans. I didn’t have to try to breastfeed again, which was very triggering for me and contributed to the bad physical health situation which, in its turn, also contributed to the PPD. I would talk to my OB early in pregnancy about getting on antidepressants and talking to a counselor, and having a plan in place if PPD still broke through all that. DH would help a lot more, and would ensure I’d get more breaks. As a result, we said, “okay, another kid does sound like a good idea, let’s try,” and there ya go. Reason. It’s awesome.