If that is the case, then is it not arguable that this choice makes the teaching overall confusing? Because if the meaning slips seamlessly between the two senses all over the canon and then at times it is only one of the senses that is intended while it is the contrary of the other sense that is also intended at the same time, it seems to me quite confusing.
I know the answer to this is that the Buddha had no other choice. But I beg to differ, as there are words for “applying the mind and keeping it connected”. Here are a few examples:
DN 2: “so evaṃ samāhite citte parisuddhe pariyodāte anaṅgaṇe vigatūpakkilese mudubhūte kammaniye ṭhite āneñjappatte ñāṇadassanāya cittaṃ abhinīharati abhininnāmeti."
“With his mind thus concentrated, purified, and bright, unblemished, free from defects, pliant, malleable, steady, and attained to imperturbability, he directs and inclines his mind to knowledge and vision.”
“bhikkhu kāye kāyānupassī viharati ātāpī sampajāno satimā, vineyya loke abhijjhādomanassaṃ. tassa kāye kāyānupassino viharato kāyārammaṇo vā uppajjati kāyasmiṃ pariḷāho, cetaso vā līnattaṃ, bahiddhā vā cittaṃ vikkhipati. tenānanda, bhikkhunā kismiñcideva pasādanīye nimitte cittaṃ paṇidahitabbaṃ. tassa kismiñcideva pasādanīye nimitte cittaṃ paṇidahato pāmojjaṃ jāyati.”
“a monk abides contemplating body as body — ardent, fully aware, mindful — leading away the unhappiness that comes from wanting the things of the world. And for one who is abiding contemplating body as body, a bodily object arises, or bodily distress, or mental sluggishness, that scatters his mind outward. Then the monk should direct his mind to some satisfactory image. When the mind is directed to some satisfactory image, happiness is born.”
Personally, I feel that the functions of applying the mind / keeping it connected to the meditation object and thinking/investigating before breaking into speech are quitedifferent, and I have a hard time seeing how the former (which is connected to only one object, like trying to keep only one activity) would be a refined form of the latter (which is connected to a great variety of objects, often at the same time, like synthesizing a larger number of simultaneous activities).
I think it could be interesting to compare brain activity between times when one meditates and times when one thinks, to see whether the task of meditating can be considered as a sub-task of thinking (just as applying the mind/keeping it connected is considered by some as a subset/ refined version of thinking/pondering).
I have made a very shallow research, and it is quite clear that a “non-thinking” task activates areas of the brain which are not activated during “thinking” tasks: see the chart on page 4/5 which I reproduce here:
Here is additional information:
In these experiments, subjects lay down in a neuroimaging device and were assigned tasks designed to encourage or discourage thinking. For instance, subjects were asked to recall images or engage in linguistic activity, and were also requested to stop thinking for 20 sec. In order to verify our previous results, we used the same tasks in this study.
Our test protocol asked subjects to picture images of (1) Kiyomizu Temple and (2) the Diet Building, (3) to recall the Chinese zodiac, (4) to recall a conversation they had earlier in the day, and (5) and (6) to not think at all (Table 1). We asked subjects to go through this series of tasks twice.
Tasks 1 and 2 stimulated subjects’ thinking by encouraging their recall of a familiar place, while Tasks 3 and 4 tested their ability to recall words. The final tasks (5 and 6) were intended to examine subjects’ capability to suspend their thinking. Our goal was to determine whether we could detect differences in brain activity between Tasks 1−4 and Tasks 5−6.
I don’t take this to be the last word on the issue of course (all the more that subjects are merely asked to not think, which is not the same as meditating), but I think the issue is worth investigating.