Learn from Me, O mighty-armed Arjuna, these five causes as declared in the Sankhya system for the accomplishment of all actions.
In simple words
Krishna teaches Arjuna about what causes action: "Learn from Me the five factors that the ancient thinkers identified as necessary for any action to happen."
Word-by-word meanings
पञ्चfiveएतानिtheseमहाबाहोO mightyarmedकारणानिcausesनिबोधlearnमेfrom Meसांख्येin the Sankhyaकृतान्तेwhich is the end of all actionsप्रोक्तानिas declaredसिद्धयेfor the accomplishmentसर्वकर्मणाम्of all actions
18.13 पञ्च five? एतानि these? महाबाहो O mightyarmed? कारणानि causes? निबोध learn? मे from Me? सांख्ये in the Sankhya? कृतान्ते which is the end of all actions? प्रोक्तानि as declared? सिद्धये for the accomplishment? सर्वकर्मणाम् of all actions.Commentary The Self has no connection whatevr with activity. Nature does everything. The Self is the silent witness. He remains indifferent. The whole superstructure of human activity is the result of the five welldefined causes which are enumerated in the following verse.Etani These Which are going to be mentioned.Sankhya Vedanta Knowledge of the Self as taught in the Vedanta (the Upanishads) puts an end to all actions. This is the reason why the term Kritante (the end of actions) is used here. When the knowledge of the Self arises? all actions terminate. This is taught in chapter II? verse 46 To the Brahman who has known the Self al the Vedas are of so much use as is a reservoir of water in a place where there is a flood everywhere. Again? in verse 33 of chapter IV? it is said All actions in their entirety? O Arjuna? culminate in knowledge. Vedanta? therefore? which imparts knowledge of the Self? is the end of action. A liberated sage who has attained the knowledge of the Self in accordance with the instructions laid down in the Vedanta becomes a Kritakritya (one who has done everything and has nothing more to do).
Contemporary scholarly and practical interpretations for modern seekers.
This interpretation draws on a specific tradition and may not represent the view of any single school. For authoritative guidance within a specific tradition, seek a qualified teacher.
Modern
Regarding the threefold renunciation, the Blessed Lord Sri Krishna had spoken of the person who performs action without ego and without attachment as a sattvic renunciate. Therefore, it is natural that Arjun's mind becomes filled with the desire to understand the true nature of action. For this reason, in the present section, the Blessed Lord Sri Krishna describes both the gross form of action as well as its subtle nature—its inspiration, purpose, and other aspects.
To accomplish any worldly or spiritual action, five causes are necessary. These are, as it were, the limbs of action, without which the fulfillment of action cannot be achieved. If a person wishes to regulate and organize his actions properly and thereby accomplish inner cultural development, then he requires great courage, continuity of purpose, self-confidence, and intellectual capacity. Therefore, the Blessed Lord here addresses Arjun by the name Mahabaho—the mighty-armed one—and calls forth his heroic spirit.
The description of the five causes necessary for the accomplishment of action is found in the Sankhya philosophy. Here, the term Sankhya refers to Vedanta, not to the Sankhya philosophy of the sage Kapila, for such a description is not found in that system. The word "kritanta" used in this verse is a qualifier of Sankhya. Kritanta means the end of actions. When the knowledge of the Self, as taught in Vedanta, is attained, the ego comes to an end, and with it, the cessation of one's actions follows.
Therefore, Vedanta is characterized as kritanta. In the next verse, those five causes are explained.