(9) Tertullian (Ad Nationes 1.12) stated: "If you position a man with his arms outstretched (manibus expansis), you have created an image of the cross (imaginem crucis). This text uses the verbexpandere "to spread across, widen" and the context shows clearly that this pose is one with the arms outstretched laterally since this image of the cross includes a crossbeam or antemna. (10) Minucius Felix (Octavius 29.6) made a very similar comparison: "A crossbeam (iugum) set up forms the sign of the cross (crucis signum), and so too does a man with outstretched hands (homo porrectis manibus)". This passage uses porrigere "to reach out", the same verb used byLactantius, and although it can be used more easily with upward extension than many of these other words discussed here (since it involves an act of reaching), it clearly refers to a reaching to the side since the pose is directly compared with the crossbeam of the cross. (11) Rufinus (Commentarius in Symbolum Apostolorum, 14): "These words, height and breadth and depth are a description of the cross (descriptio crucis).... by breadth the right hand and the left that extend outwards (latitudinem quoque illam quae distenta in dextram laevamque manus)". This image here is one of the two hands extended laterally, one on the right side and one on the left. The verb distendere, again, is the same one used by Senecaand Aulis Gellius, and it emphasizes that the hands are stretched apart in different directions. (12) Finally, we may quoteAugustine of Hippo (De Doctrina Christiana 2.41.62): "Of the cross of the Lord (crucem domini), its breadth (latitudo) is signified by the transverse beam on which the hands are stretched out (in transverso ligno quo extenduntur manus)". This is another clear reference to the hands being stretched out laterally from one side to another, for it explicitly mentions the hands being stretched out upon a transverse beam (in transverso ligno). Taken together, the verbs extendere, distendere, dispandere, diducere, explicare, expandere, and porrigere collectively fit an expansion along a crossbeam much better than an upward extension on the upright. Porrigere, for example, may be used of upward extension, but the two instances here are clearly described as lateral extension.
When a man was tied to a stipes (see here ), he had his arms above his head, stretched along the post. Whether to describe the attitude that the body takes, you could say that the arms are "extended" because that is the upper limbs of body that are abnormally expanded in this torture. Moreover, Seneca, who observed executions in his time, mentions this feature of the body when it tells of a man at the stake: "districtus (...) membra."
A further passage in Seneca (De Vita Beata 19.3) is noteworthy, tho it doesn't mention the hands or arms unambiguously: "They are stretched upon as many crosses as their own desires (quot cupiditatibus tot crucibus distrahuntur)"; the verb here is distrahere "draw in different directions, separate forcibly, divide apart", a meaning very similar to that of distendere. Since "stretching" in crucifixion was otherwise almost unanimously in reference to hands/arms/limbs, distrahere could possibly be added to the list as another word that more felicitously pertains to the stretching of the arms on a crossbeam than on the upright post. What is conspiciously missing in this group are words that more clearly suggest upward extension of the hands, such as erigere "reach up, make erect" (likeporrigere a form of rigere "to reach"), surrigere "to raise, lift up", or elevare, allevare, levare "to lift up, raise". This may be illustrated in the use of such words in passages that do discuss the upright. So Rufinus (Commentarius in Symbolum Apostolorum, 14) wrote: "By height he meant the part which stretches above the earth and towers upwards (altitudunum vero illam quae super terram porrecta sublimis erigitur)". In addition to porrigere, Rufinus uses erigere to refer to the extension upwards of the upright pole. So in short, the word patibulum pertained both to a horizontal beam used with doors and a beam used in the lateral extension of the hands from side to side in the punishment of slaves and criminals, especially in the case of crucifixion.
Now, to return to the passage of Seneca which you refer, On the happy life - XIX-, patibulum is used interchangeably with stipes for the following reason:
In the context, the writer made a presentation on the virtue and the way the great philosophers like Epicurus, have sought and advocated by their teachings. Seneca speaks in particular of all those who despised them because these philosophers were not living in accordance with what they taught. Seneca takes so their defense by explaining that the important thing was primarily to seek virtue, that these philosophers were trying to do despite their imperfections and their inability to achieve their ideals. Seneca criticized so openly to all those who denigrated these philosophers to be slaves to their greed and their selfish passions. Far from being virtuous, the life of these men was only meanness, tightness and mental distress in contrast to the serenity enjoyed by those philosophers who tended to their high ideals. To illustrate the degree of suffering that must have felt these critics, who were harming themselves by rejecting virtue, Seneca compares each one to a man who "crucify" himself. They wrote:
"You say that not one of [these philosophers] do not realize what he says and lives according to his maxims. No wonder, when their words are so heroic, so sublime, so high dominate all storms human life when they are not meant to tear at least of these crosses [Lat. crucibus] where all, as you are, hold your hands the nails that tear you? "
Seneca compares the mental suffering that these men suffered, they were wrong in themselves, to 'crucibus' on which is nailed themselves. They were, somehow, their tormentor, unlike philosophers who tried to break away from these "cross" by seeking virtue which preserved them from "all the storms of life", as the fact being torn by greed. To show how this suffering was unbearable, and the condition of these greedy men was very poor, Seneca will compare each of them to a torture victim who suffers several simultaneous or successive punishment. Of course, this situation could not happen in reality because we could not attach the same sentenced to several posts at once, or subject it to more of a "crucifixion", the latter leading to death systematically. Seneca writes thus:
"The tortured [in reality] is suspended at least only one pole [Lat. Stipitibus]; those who are abusers themselves [figuratively speaking] suffer many crosses [Lat. Crucibus] that passions of the tug. "
The antithesis of Seneca is meaningful only if "crucibus" is the punishment that the word "stipitibus" evokes, ie the execution of a "stake". The contrast is illustrated by the difference in the number of executions and not in the way that the convict is executed. In reality, the victim suffered "a single [Lat. Singulis] post", so figured, critics philosophers suffer "as much as passions that cross the tug." This antithesis arises a similar meaning to the words and stipes crux, ie "post." Seneca then ends his comparison about the attitude of these "crucified" in the figurative sense: "slanderers however, is to insult others they have graciously. I could not see a hobby, was that some men spew their gallows (lat. patibulo) on those who watch them. ". Denigration, by which these men were critical of the philosophers, he was a "hobby" harmless? No, these men were contemptuous, driven by a relentless hatred which prompted them to boo those seeking virtue. They behaved like those "crucified" spitting their gallows, or patibulum on those who observed them. Again, the term patibulo be understood in the sense of stipitibus or crucibus, since it also falls within the framework of the antithesis.
Thus, Seneca has indeed used the terms crux and patibulum within the meaning of a single vertical post (stipes).