The Dhammapada opens with mind as the forerunner of all states, and the two verses that follow are a matched pair: speak or act with a corrupted mind and suffering follows like the cartwheel behind the ox; speak or act with a clear one and happiness follows like a shadow that does not leave. It is not a claim that thinking makes things so. It is a claim about causation running the other way from where most people look for it — that the quality of experience is set upstream of circumstance, in intention, and that this is the leverage point the whole path works on.