Designative Force Of Thought
(Orlah 1:1 1a lines 16-19)
Our Mishnah teaches: “One who plants for a fence or for beams is absolved from Orlah”. In Rabban Shimon Ben Gamaliel’s understanding of the Mishnah the designation for a fence or beam is a mental one. The planter designates the growth mentally to be for the purpose of serving as a fence or as a beam.
The Mishnah’s ruling is stated without qualification and applies regardless of whether a plant is fit to be used as a fence or beam or only as food. According to the Mishnah, mere mental designation suffices in removing any growth from its Orlah designation.
In the opinion of Rabban Shimon Ben Gamaliel, however only those growths which are actually suitable to serve as a fence or beams may be absolved from Orlah. This would exclude, for example, grape vines which one designates to serve as beams. According to Rabban Shimon ben Gamaliel, mere mental designation does not carry enough force to absolve something unsuitable for serving as a fence or beam from its Orlah obligation. [The Talmud, although implicitely shares in Rabban Shimon ben Gamliel’s interpretation of the Mishnah and his differal with it inquires why it is that the Mishnah absolves one who designates something unsuitable to serve as a fence or beam from Orlah.]
In Rabbi Ze’ira’s understanding of the Mishnah the designation for a fence or beam is a physical one. The planter designates the growths to serve as a fence or beam by planting them in a configuration suitable for a fence or beam. According to Rabbi Ze’ira’s interpretation of the Mishnah, a physical act of designation is required, not merely a mental one to absolve a plant from its Orlah obligation, even if the plant is suitable to serve as a fence or beam.
At the beginning of Tractate Terumoth (1:1 1a) the Talmud inquires to what extent if at all a physical act of a child or mentally handicapped person who do not have da’at can be taken as an affirmation of determination and concludes that a physical act can in fact affirm determination. The Mishnah here may maintain that determination can only be affirmed by means of a physical act.