In a comment to the post on Phil 1.11 Andrew Wilson raised an interesting question/issue. With his permission I have copied it here:
To put the problem of evidence for lectio difficilior into context, Royse's and Head's studies showed the ratio of singular omissions to singular additions among early papyri running at about 75:25 (in percentage terms, or, for every three omissions you get one addition). That sort of evidence, to me, is incontrovertible - scribes omitted far more often than they added.
But, my figures for lectio difficilior (based on over 2000 singular readings) show a ratio of over 200 harder readings to about 10 easier readings (20:1), or putting it into percentages: 95% harder readings to 5% easier. Those sorts of ratios, to me, put lectio difficilior out of business.
However, when I mention these sorts of figures to textual critics, most instinctively (think knee-jerk reaction) spring to the defence of the canon. The problem is that some of these defences are poorly-thought-out, almost as if the canon must be defended at all costs.
Let me give two examples:
1. Easier readings would be more attractive to subsequent copyists, and more likely to be perpetuated, whereas harder readings are more likely to be later corrected. Therefore, the fact that harder readings predominate among singulars means little because the long-term effect on textual transmission would be in the opposite direction. To me, this objection (a) is circular reasoning, for it assumes what it should be proving (that scribes try to improve the text, rather than introduce further difficulties), (b) is not based on any evidence - the question of at what point a reading becomes so difficult that it tempted scribes to alter it should be one for evidence to determine, not armchair speculators, and (c) it puts the canon beyond the reach of any contrary evidence. It is like the story of the man whistling in Chicago who said he was whistling to keep the tigers away. When it was pointed out that there were no tigers in Chicago, he replied: 'See, it works'.
2. A second defence involves introducing the issue of intentionality by claiming that lectio difficilior only applies to intentional changes. This defence, likewise, brings with it questions and problems. (1) It apears to commit the fallacy of the excluded middle - it ignores the possibility that a reading might have been created in more than one stage, as a result of a wandering mind or as a salvage reading of an earlier nonsense reading. (2) Even if we cull nonsense readings and cases of hom. from the count (as likely to be unintentional changes), we are still left with easier readings as an extreme minority, for the great majority of singular readings remaining are neutral or harder. This leaves the 'nuanced' defender of lectio difficilior with a conundrum. Either intentional changes to the text rarely seem to result in an improved text or, alternatively, the vast majority of textual changes must have been unintentional (even though they appear otherwise). Either way, the objection (and lectio difficilior) fails. In short, the objection does not dispose of anywhere near enough evidence to stand.
And this is where I would like some help ... Are there any other good defences of lectio difficilior that I should be considering?