You can use academic sources when arguing in court if you like, but be aware of the following:
- Academic texts are not primary sources of law in Jamaica. What is in them may be persuasive but does not bind a court in the same way as statute law or case law. Sometimes, it's appropriate to cite works of legal scholarship to flesh out an argument. If the book contains a succinctly-phrased statement that matches what you want to prove, but prior case law isn't quite as neatly applicable, then you might cite both - subject to points below. Citing the book alone is weaker. At other times, when there is authority on both sides of a point, you might find academic argument tipping the balance, but again not to be used in isolation.
- Whether a text is persuasive may not be obvious, especially for older works. Sometimes, perhaps often, the law has changed since the book was published. Don't assume that an old book by a famous author will automatically be revered. You can check to see if newer books say something different from the older one, and in general start your search looking backwards from now in order to identify the current state of the law. It is more common these days to see references to current editions of textbooks than comparatively ancient authorities, no matter how illustrious the name of Blackstone might be.
- If a point of law is not actually contested, then there is no need to argue about it. It can form part of the background material that is agreed on between the parties. Basic principles of the way contracts work don't need elaboration or authority.
- Judges would prefer to have you limit the number and range of authorities you bring in, because they only have so much time in their day and they don't want to struggle through a lot of unnecessary background reading. In a skeleton argument, the strong preference is for only one principal authority to be mentioned in support of each point of law. You can mention a recent decisive case rather than reciting the entire history of case-law on the topic, and you don't need to include cases where a well-understood precedent was applied without difficulty. It may be that a textbook brings you to the relevant statute or judgement but then that is what you need to cite, not the textbook itself, especially if it simply quotes or restates what is found in the primary material.
- For filing court documents in general, pay close attention to the Civil Procedure Rules and the Practice Directions, including PD No. 8 of 2020 on the format of the judge's bundle.
- If the judge is annoyed enough about non-compliance with the court's rules about submissions, then various sanctions are available to them. For example, they can refuse costs on the legal research that led to the preparation of the submission.
In correspondence, which I think you allude to, you can be more free than when dealing with the judge's bundle. In a letter to the opposing party you can certainly bring in additional references that you think would be helpful to you as a matter of rhetoric and argumentation. Do note that doesn't mean it is a good idea to make correspondence too aggressive or lengthy. For one thing, a judge can end up reviewing the correspondence and will notice whether or not you are making a good-faith effort to resolve the matter, or at least identify the salient issues to bring to the court.