Girsah – Surface study, is the understanding of the subject at first glance, without stopping to delve into its details with any great scrutiny or analysis. In Talmud study, this is used mainly to cover much ground and gain a broad familiarization with the subject matter. However, since it does not involve in-depth investigation, the knowledge gained is inherently shallow. This is analogous to a ship sailing on the surface of the ocean, rather than a submarine which submerges into its very depths. It is similar to one who casually glances at an object he is unfamiliar with, without scrutinizing it carefully in his mind, to understand what it is and how it is. He makes no attempt to understand its depth by examining all its inner and external components, but, rather, takes it at face value. Because of this, he may forget it completely with the passage of time. If asked, he will find it difficult to describe and even if he does describe it, it will be in the most general of terms. This is because he only saw it in a passing way, and did not examine it carefully.
It is for this reason that witnesses to a crime will often have hazy or disparate recollections of the incident, since they only saw it in a passing way. In contrast, a detective or police officer, who witnesses a crime, will take notice of the details, because after years of experience, he has developed a “trained eye”. He has accustomed himself to notice details.
The same is true of the “mind’s eye”, which “observes” concepts, so to speak. When one studies in a way of Girsah (Surface study), he understands the subject in a passing way. He will, therefore, only grasp it in the most general of terms and will quickly forget the details. Since he has not plumbed the subject to its depths, his understanding of it will be external and general and he will be incapable of explaining it in detail. He will be able to explain it only in the most general of terms.
Before explaining Iyun (In depth analysis) we must first understand the makeup of any intellectual concept.