Science can provide useful insights, but the practice of actually existing scientific institutions is fraught with politics and every type of irrationality you can imagine. Science only provides a method and the implementation of the method is usually flawed, and of course heavily distorted by capitalism and militarism. There are not many careers to be made out of trying to reproduce results, and so often shaky conclusions are believed as facts for a long time. It's similar to building software without bothering to look for or fix bugs.

It was Bronowski who said that science represents the best we can know despite our fallibility as humans.