什么是弥尔的方法

弥尔在他的《逻辑学体系》（System of logic, 1843）所区辨出来的五种实验推论的方法。假设有个人，对於在一组特定的条件下，对於决定，什麽因素在引起特定的结果（称为结果E）中所扮演的角色，感到有兴趣。一致性的方法告诉我们，要去寻找，出现在所有结果E发生的情况下的因素。差异性的方法告诉我们，要去寻找某些在结果E发生的情况下的因素，以及当结果E并未发生的另一个相似情况下所欠缺的某些因素。一致性与差异性的联合方法，结合前两种方法。残余（residues）的方法应用在，当结果E的部分，可藉指涉已知的因素加以解释；这个方法并告诉我们，将「残余」归之於其余当结果E发生的条件。相伴变项的方法，则是运用在当结果E能够以不同的程度出现时；如果我们确认一个因素F，诸如气温，它的变项与结果E的变项，如尺寸，有正相关或负相关的关系。而後我们能够指出因素F在因果上与结果E相关连。

Mill's methods

Five methods of experimental reasoning distinguished by John Stuart Mill in his System of Logic (1843). Suppose one is interested in determining what factors play a role in causing a specific effect, E, under a specific set of circumstances. The method of agreement tells us to look for factors present on all occasions when E occurs. The method of difference tells us to look for some factor present on some occasion when E occurs and absent on an otherwise similar occasion when it does not. The joint method of agreement and difference combines the two previous methods. The method of residues applies when part of E is explicable by reference to known factors, and tells us to attribute the "residue" to the remaining circumstances under which E occurs. The method of concomitant variation is used when E can be present in various degrees; if we identify a factor F, such as temperature, whose variations are positively or negatively correlated with variations in E, for instance, size, then we can infer that F is causally connected with E.