| Sources of law | Formal—source of the authority of the law. |
| Material—source of the contents of the law. |
| Material sources | Legal—immediate and legally recognised. |
| Historical—remote and not legally recognised. |
| Legal sources | 1. Legislation—enacted law. |
| 2. Custom—customary law. |
| 3. Precedent—case-law. |
| 4. Professional opinion—juristic law. |
| 5. Agreement—conventional law. |
| Grounds of the recognition of these sources. |
| Operation of sources | Constitutive—adding new law to old. |
| Abrogative—substituting new law for old. |
| Extent of abrogative power possessed by the sources. |
| Relation between sources of law and sources of rights. |
| Legal principles | Ultimate—without legal sources. |
| Derivative—drawn from legal sources. |