| The Valid Syllogisms |
| Figure 1 | Figure 2 | Figure 3 | Figure 4 | ||
| M p | p M | M p | p M | ||
| s M | s M | M s | M s |
| UNconditionally Valid |
| AAA | EAE | IAI | AEE | ||
| EAE | AEE | AII | IAI | ||
| AII | EIO | OAO | EIO | ||
| EIO | AOO | EIO |
| Aristotelian or Conditionally Valid |
| Validity condition | |||||
| S exists | AAI | AEO | AEO | ||
| EAO | EAO | ||||
| M exists | AAI | EAO | |||
| EAO | |||||
| P exists | AAI |