The first is a loose chain of reflections. Siris does not present a rigorous argument; it is a speculative work, not an argumentative one. This is not to say that there is no argumentation at all in Siris. The reflections occasionally present arguments for this or that, and the whole work can actually be considered a form of argumentation (which is slightly different from being an argument in the strict sense). The primary purpose of the work is not to constrain belief, but to inspire thought. In this respect it has affinities with his 1735 work, The Querist, which, while on a different topic (economics), was also primarily devoted to the inspiring of thought rather than the presentation of a rigorous argument. It did this by simply asking a long series of questions (hence the title, The Querist), most of which are rhetorical. Here is a sample:
QUERY 1 Whether there ever was, is, or will be, an industrious nation poor, or an idle rich?
2 Whether a people can be called poor, where the common sort are well fed, clothed, and lodged?
3 Whether the drift and aim of every wise State should not be, to encourage industry in its members? And whether those who employ neither heads nor hands for the common benefit deserve not to be expelled like drones out of a well-governed State?
4 Whether the four elements, and man's labour therein, be not the true source of wealth?
5 Whether money be not only so far useful, as it stirreth up industry, enabling men mutually to participate the fruits of each other's labour?
This genre derives, I suspect, from Sir Isaac Newton, who presented a set of queries in his Optics. Since Newton was interested in experiments rather than abstract reasoning, his queries are primarily ideas for research projects, but it is easy to see how the form could have been adapted. (If anyone has come across a more likely pedigree, let me know.) The querist genre has many useful advantages. It is flexible, since it allows the author considerable control over the discussion while allowing the reader considerable control over the precise details of the arguments. In effect, it breaks the reasoning down into a dialogue between author and reader by presenting just the starting points of thought. Another aspect of its flexibility is that it can be used to present both very tentative ideas and obvious common-sense conclusions, an effect of the continual use of questions. If some genres of writing are very good for presenting well-formed arguments (e.g., the standard philosophical essay), the querist genre is very good for presenting initiating ideas. As I noted above, it is more for inspiring thought than constraining belief.
With Siris Berkeley is doing much the same thing as he had already done in The Querist, but here he has chosen to use reflections rather than queries. This sacrifices some of the flexibility of the querist genre, but it gives Berkeley more control over the thought, and so is better suited for presenting topics that might be too complicated for presentation in simple querist form. This is precisely what Siris needs, for its topics are complicated. This brings us to the second chain.
The second chain is from tar-water to the Trinity. Siris covers the entire universe. By a surprisingly cogent line of reasoning moves from tar as a folk medicine through the causes of its efficacy to the basic causal principles order the universe, to God as the cause of this order, finally terminating in suggestive thoughts about philosophical approximations to the Trinity. As Berkeley describes the course of reasoning in his poem "On Tar":
Vain images possess the sensual mind,
To real agents and true causes blind.
But soon as intellect's bright sun displays
O'er the benighted orb his fulgent rays,
Delusive phantoms fly before the light,
Nature and truth lie open at the sight:
Causes connect with effects supply
A golden chain, whose radiant links on high
Fix'd to the sovereign throne from thence depend
And reach e'en down to tar the nether end.
It is, without doubt, an extraordinary, astonishing, and unique work.
I have decided to name my weblog 'Siris' for a number reasons. The first is that I have, like many who have been exposed to him, a profound affection for Berkeley's thought, even when I think he is completely wrong, and like the eccentric brilliance of Siris itself, my favorite out of all his works. The second is that I like the ambition of Berkeley's Siris: if I am going to have a blog, it will be one that's not afraid to cover everything philosophical from tar-water to the Trinity. The third is that the name seems appropriate given that I'll probably be posting a great deal related to my work in early modern philosophy, of which Berkeley is an eminent example. Besides, it just sounds easy on the ear.
As to those who like shorter postings, don't worry; they won't all be as long as this one!