What is the law of karma? The principle of making good in a subsequent incarnation what was reprehensible in a preceding one. Differentiation must be made between karma that takes effect inwardly and one that has more external results. Karma taking effect inwardly is connected with the forming of character, talents and habits. Karma that manifests in more external ways takes the form of the conditions of life in which a man is placed, such as family, nationality and so forth. We will now consider more closely how karma works in physical life.
For example, what appears in one life as urge or impulse, desire and ideation, emerges in the next life, or one of the following lives, as habit. From good habits a fine, well-knit, healthy physical body will come into existence in the next incarnation. A bad habit makes (in RS Archive is used the word ‘snakes’) its appearance in another life in the form of an illness or as a tendency to illness. Thus, the causes of illnesses are to be sought in the inclinations and habits of a previous life.
The actual destiny of an individual is, on the contrary, the result of his former deeds. A person who radiates much love in one life will, in another, be able to stay young, inwardly as well as outwardly, for a long time. A person who harbors many feelings of hatred in one life will age prematurely in another. Individuals who abandon themselves to an ordinary, indolent life, which avoids all forms of spirituality, deprive themselves of something for their subsequent life that will be difficult for them to retrieve.
Source: Rudolf Steiner – GA 109 – Rosicrucian Esotericism: X: On Karma, Reincarnation and Initiation – Budapest, 12th June 1909
Translated by Dorothy S. Osmond