The facial-feedback hypothesis argues, however, that the causal relationship between emotions and facial expressions can also work in the opposite direction.
然而，面部反馈假说认为，情绪和面部表情之间的因果关系可能反过来也是成立的。
2
However, there is insufficient evidence at present to support the hypothesis that depression has a direct causal relationship with subsequent dementia.
不过，目前尚无足够的证据支持抑郁与随后的痴呆有直接因果关系的假设。
3
The Causal Principle is a hypothesis while causality shows the order of nature and is the core of the order and necessity is the prerequisite for science as well as the basis of the causal concept.