Feelings are truth
The only unconditional truth is feelings.
If we feel good, then no one can tell us that we feel bad. Our feelings are irrefutable. If you feel bad, but someone tells you the opposite, then it’s false.
A book that made us feel bored, and we made an opinion based on that is a true opinion—because we felt so. It doesn’t necessarily mean that the book will be boring to everyone, but for us, it is an unquestionable truth.
Finding truth is understanding feelings, our own and others’, naming them and reasoning upon them using logic.