Written v. Physical
Whilst the study of archaeology itself focuses solely on physical sources (artefacts), it is necessary for archaeologists to study a variety of written sources about the same topic in order to produce a cohesive and logical story. Conversely, studying written sources can provide contrasting opinions about the certain topic the archaeologist is studying, disregarding certain opinions already established beforehand. However, this process is necessary to ensure that the most logical and common story is achieved, and eventually accepted. For example, the accounts of Roman historian Tacitus regarding tribal sacrifices for the Spring Goddess, Mother Earth match up with the archaeological findings of bog bodies. Some of these bodies' last meals were a spring soup, and the manner in which they were killed were all similar enough to warrant the suspicion of a traditional and widespread spring-associated sacrifice. This suspicion could then be backed by the evidence of Tacitus' writings, solidifying what could not have been much more than an educated guess.
Another example of written sources aiding the physical sources is that of Lindow Man and the sacrifice to the sun god Belenos. Without the written sources explaining and detailing the ritualistic sacrifice to Belenos, there would be no explanation as to why Lindow Man's last meal was burnt griddlecake, and his death would remain purely speculative. In addition, without these initial written sources, archaeologists (and essentially modern historians) such as Rick Turner would not have been able to express their opinions on Lindow Man, and their explanations for the ritualistic sacrifices would have no evidence to back it up.
Another example of written sources aiding the physical sources is that of Lindow Man and the sacrifice to the sun god Belenos. Without the written sources explaining and detailing the ritualistic sacrifice to Belenos, there would be no explanation as to why Lindow Man's last meal was burnt griddlecake, and his death would remain purely speculative. In addition, without these initial written sources, archaeologists (and essentially modern historians) such as Rick Turner would not have been able to express their opinions on Lindow Man, and their explanations for the ritualistic sacrifices would have no evidence to back it up.